diff --git a/_build/test/Tests/Model/modParserTest.php b/_build/test/Tests/Model/modParserTest.php
index 545264f8258..eee4359aef9 100644
--- a/_build/test/Tests/Model/modParserTest.php
+++ b/_build/test/Tests/Model/modParserTest.php
@@ -11,7 +11,9 @@
  */
 namespace MODX\Revolution\Tests\Model;
 
-
+use MODX\Revolution\modElementPropertySet;
+use MODX\Revolution\modPropertySet;
+use MODX\Revolution\modSnippet;
 use MODX\Revolution\modX;
 use MODX\Revolution\MODxTestCase;
 use MODX\Revolution\MODxTestHarness;
@@ -764,23 +766,188 @@ public function providerProcessElementTags() {
             ],
             // tags directly within brackets
             // @todo this test fails
-//            [
-//                [
-//                    'processed' => 1,
-//                    'content' => '<input type="text" name="item[Tag2][name]" />'
-//                ],
-//                '[[+tag1:notempty=`<input type="text" name="item[[[+tag2]]][name]" />`]]',
-//                [
-//                    'parentTag' => '',
-//                    'processUncacheable' => true,
-//                    'removeUnprocessed' => false,
-//                    'prefix' => '[[',
-//                    'suffix' => ']]',
-//                    'tokens' => [],
-//                    'depth' => 1
-//                ]
-//            ],
+            // [
+            //     [
+            //         'processed' => 1,
+            //         'content' => '<input type="text" name="item[Tag2][name]" />'
+            //     ],
+            //     '[[+tag1:notempty=`<input type="text" name="item[[[+tag2]]][name]" />`]]',
+            //     [
+            //         'parentTag' => '',
+            //         'processUncacheable' => true,
+            //         'removeUnprocessed' => false,
+            //         'prefix' => '[[',
+            //         'suffix' => ']]',
+            //         'tokens' => [],
+            //         'depth' => 1
+            //     ]
+            // ],
+
+            // #16318 parsing tags with @ in the value causes it to break the tag
+            [
+                [
+                    'processed' => 1,
+                    'content' => "aaa
+[[nonExistentSnippet? &x=`bbb@ccc`]]
+ddd
+eee"
+                ],
+                "[[+empty_content:empty=`aaa
+[[nonExistentSnippet? &x=`bbb@ccc`]]
+ddd
+`]]eee",
+                [
+                    'parentTag' => '',
+                    'processUncacheable' => true,
+                    'removeUnprocessed' => false,
+                    'prefix' => '[[',
+                    'suffix' => ']]',
+                    'tokens' => [],
+                    'depth' => 0
+                ]
+            ]
+        ];
+    }
+
+    /**
+     * @dataProvider providerPropertySetCall
+     * @param $content
+     * @param $expected
+     * @param $propertySet
+     * @param $params
+     * @return void
+     */
+    public function testPropertySetCall($content, $expected, $propertySet, $params)
+    {
+        /** @var modPropertySet $set */
+        $set = $this->modx->newObject(modPropertySet::class);
+        $set->set('name', 'propset_' . bin2hex(random_bytes(4)));
+        $set->setProperties($propertySet);
+        self::assertTrue($set->save());
+
+        /** @var modSnippet $set */
+        $snippet = $this->modx->newObject(modSnippet::class);
+        $snippet->set('name', 'snippet_' . bin2hex(random_bytes(4)));
+        $snippet->set('content', '<?php
+        return $scriptProperties["prop"] ?? "";');
+        self::assertTrue($snippet->save());
+
+        $join = $this->modx->newObject(modElementPropertySet::class);
+        $join->fromArray([
+            'element' => $snippet->get('id'),
+            'element_class' => $snippet->_class,
+            'property_set' => $set->get('id'),
+        ], '', true);
+        $join->save();
+        self::assertTrue($join->save());
+
+        $content = str_replace('propSetName', $set->get('name'), $content);
+        $content = str_replace('snippetName', $snippet->get('name'), $content);
+
+        $c = $content;
+
+        $this->modx->parser->processElementTags(
+            $params['parentTag'],
+            $content,
+            $params['processUncacheable'],
+            $params['removeUnprocessed'],
+            $params['prefix'],
+            $params['suffix'],
+            $params['tokens'],
+            $params['depth']
+        );
+
+        $set->remove();
+        $snippet->remove();
+        $join->remove();
+
+        $this->assertEquals($expected, $content, "Did not get expected results from parsing {$c}.");
+    }
+    public function providerPropertySetCall()
+    {
+        // In this test, snippetName and propSetName are replaced with a random string
+        // for each run
+        return [
+            [
+                '[[snippetName? &prop=`123`]]',
+                '123',
+                [],
+                [
+                    'parentTag' => '',
+                    'processUncacheable' => true,
+                    'removeUnprocessed' => false,
+                    'prefix' => '[[',
+                    'suffix' => ']]',
+                    'tokens' => [],
+                    'depth' => 10
+                ]
+            ],
+            [
+                '[[snippetName@propSetName]]',
+                '123',
+                [
+                    'prop' => '123',
+                ],
+                [
+                    'parentTag' => '',
+                    'processUncacheable' => true,
+                    'removeUnprocessed' => false,
+                    'prefix' => '[[',
+                    'suffix' => ']]',
+                    'tokens' => [],
+                    'depth' => 10
+                ]
+            ],
+            [
+                '[[snippetName@propSetName? &otherProp=`foo`]]',
+                '789',
+                [
+                    'prop' => '789',
+                ],
+                [
+                    'parentTag' => '',
+                    'processUncacheable' => true,
+                    'removeUnprocessed' => false,
+                    'prefix' => '[[',
+                    'suffix' => ']]',
+                    'tokens' => [],
+                    'depth' => 10
+                ]
+            ],
+            [
+                '[[snippetName@propSetName? &prop=`123`]]',
+                '123',
+                [
+                    'prop' => '456', // needs to be ignored because &prop is specified as override
+                ],
+                [
+                    'parentTag' => '',
+                    'processUncacheable' => true,
+                    'removeUnprocessed' => false,
+                    'prefix' => '[[',
+                    'suffix' => ']]',
+                    'tokens' => [],
+                    'depth' => 10
+                ]
+            ],
+            [
+                'This is a [[snippetName@propSetName:default=`default value`]]',
+                'This is a default value',
+                [
+                    'otherProp' => 'not this one', // props other than the test 'prop' should have no effect on output
+                ],
+                [
+                    'parentTag' => '',
+                    'processUncacheable' => true,
+                    'removeUnprocessed' => false,
+                    'prefix' => '[[',
+                    'suffix' => ']]',
+                    'tokens' => [],
+                    'depth' => 10
+                ]
+            ],
         ];
+
     }
 
     /**
diff --git a/core/src/Revolution/modElement.php b/core/src/Revolution/modElement.php
index 55d9a3b62c6..ef1f0f992ba 100644
--- a/core/src/Revolution/modElement.php
+++ b/core/src/Revolution/modElement.php
@@ -726,19 +726,23 @@ public function getPropertySet($setName = null)
     {
         $propertySet = null;
         $name = $this->get('name');
-        if (strpos($name, '@') !== false) {
-            $psName = '';
-            $split = xPDO:: escSplit('@', $name);
-            if ($split && isset($split[1])) {
-                $name = $split[0];
-                $psName = $split[1];
-                $filters = xPDO:: escSplit(':', $setName);
-                if ($filters && isset($filters[1]) && !empty($filters[1])) {
-                    $psName = $filters[0];
-                    $name .= ':' . $filters[1];
-                }
-                $this->set('name', $name);
-            }
+
+        $startFiltersIndex = strpos($name, ':');
+
+        if ($startFiltersIndex !== false) {
+            $tagStart = mb_substr($name, 0, $startFiltersIndex);
+            $tagEnd = mb_substr($name, $startFiltersIndex);
+        } else {
+            $tagStart = $name;
+            $tagEnd = '';
+        }
+
+        if (strpos($tagStart, '@') !== false) {
+            $split = xPDO:: escSplit('@', $tagStart);
+            $psName = $split[1];
+
+            $this->set('name', $split[0] . $tagEnd);
+
             if (!empty($psName)) {
                 $psObj = $this->xpdo->getObjectGraph(modPropertySet::class, '{"Elements":{}}', [
                     'Elements.element' => $this->id,
diff --git a/core/src/Revolution/modTag.php b/core/src/Revolution/modTag.php
index 6120511f557..a397c5ea72e 100644
--- a/core/src/Revolution/modTag.php
+++ b/core/src/Revolution/modTag.php
@@ -511,19 +511,23 @@ public function getPropertySet($setName = null)
     {
         $propertySet = null;
         $name = $this->get('name');
-        if (strpos($name, '@') !== false) {
-            $psName = '';
-            $split = xPDO:: escSplit('@', $name);
-            if ($split && isset($split[1])) {
-                $name = $split[0];
-                $psName = $split[1];
-                $filters = xPDO:: escSplit(':', $setName);
-                if ($filters && isset($filters[1]) && !empty($filters[1])) {
-                    $psName = $filters[0];
-                    $name .= ':' . $filters[1];
-                }
-                $this->set('name', $name);
-            }
+
+        $startFiltersIndex = strpos($name, ':');
+
+        if ($startFiltersIndex !== false) {
+            $tagStart = mb_substr($name, 0, $startFiltersIndex);
+            $tagEnd = mb_substr($name, $startFiltersIndex);
+        } else {
+            $tagStart = $name;
+            $tagEnd = '';
+        }
+
+        if (strpos($tagStart, '@') !== false) {
+            $split = xPDO:: escSplit('@', $tagStart);
+            $psName = $split[1];
+
+            $this->set('name', $split[0] . $tagEnd);
+
             if (!empty($psName)) {
                 $psObj = $this->modx->getObject(modPropertySet::class, ['name' => $psName]);
                 if ($psObj) {