diff --git a/shell/assets/translations/en-us.yaml b/shell/assets/translations/en-us.yaml
index 7d037bb18b0..802aa696054 100644
--- a/shell/assets/translations/en-us.yaml
+++ b/shell/assets/translations/en-us.yaml
@@ -483,6 +483,8 @@ addonConfigConfirmation:
 
 addProjectMemberDialog:
   title: Add Project Member
+  duplicateRolesError: This member already has all of the selected roles in this project. No new assignments were created.
+  duplicateRolesSkipped: "One or more selected roles were skipped because they are already assigned to this member in this project."
 
 authConfig:
   slo:
diff --git a/shell/components/ExplorerMembers.vue b/shell/components/ExplorerMembers.vue
index 0ba95cd155c..2b002c2fb4a 100644
--- a/shell/components/ExplorerMembers.vue
+++ b/shell/components/ExplorerMembers.vue
@@ -62,17 +62,40 @@ export default {
       });
     }
 
+    // Fetch projects first so we can scope the PRTB request to this cluster's projects only.
+    // Fetching all PRTBs globally without a filter causes the Norman API's page limit to be
+    // hit before cluster-specific results are loaded, resulting in most bindings being invisible
+    // after client-side filtering.
+    const allProjects = await this.$store.dispatch('management/findAll', { type: MANAGEMENT.PROJECT });
+
+    this['projects'] = allProjects;
+
     if (projectRoleTemplateBindingSchema) {
-      this.$store.dispatch('rancher/findAll', { type: NORMAN.PROJECT_ROLE_TEMPLATE_BINDING, opt: { force: true } }, { root: true })
-        .then((bindings) => {
-          this['projectRoleTemplateBindings'] = bindings;
-          this.loadingProjectBindings = false;
-        });
+      const clusterId = this.$store.getters['currentCluster'].id;
+      // Norman projectId format is 'clusterId:projectNamespace' (e.g. 'local:p-v679w').
+      // Management project id format is 'clusterId/projectNamespace' — replace '/' with ':'.
+      // projectId is a proper Norman reference field and is safe to filter on; namespaceId is
+      // a mapper-moved field that may not be indexed for filtering.
+      const projectIds = allProjects
+        .filter((p) => p?.spec?.clusterName === clusterId)
+        .map((p) => p.id.replace('/', ':'))
+        .filter(Boolean);
+
+      if (projectIds.length > 0) {
+        // Norman's _in filter does not split comma-separated values — each value must be
+        // a separate repeated query parameter (e.g. ?projectId_in=a&projectId_in=b).
+        const url = `/v3/projectroletemplatebindings?${ projectIds.map((id) => `projectId_in=${ encodeURIComponent(id) }`).join('&') }`;
+
+        this.$store.dispatch('rancher/findAll', { type: NORMAN.PROJECT_ROLE_TEMPLATE_BINDING, opt: { force: true, url } }, { root: true })
+          .then((bindings) => {
+            this['projectRoleTemplateBindings'] = bindings;
+            this.loadingProjectBindings = false;
+          });
+      } else {
+        this.loadingProjectBindings = false;
+      }
     }
 
-    this.$store.dispatch('management/findAll', { type: MANAGEMENT.PROJECT })
-      .then((projects) => (this['projects'] = projects));
-
     const hydration = {
       normanPrincipals:  this.$store.dispatch('rancher/findAll', { type: NORMAN.PRINCIPAL }),
       mgmt:              this.$store.dispatch(`management/findAll`, { type: MANAGEMENT.USER }),
@@ -186,7 +209,7 @@ export default {
       });
 
       // We need to group each of the TemplateRoleBindings by the user + project
-      const userRoles = [...fakeRows, ...this.filteredProjectRoleTemplateBindings].reduce((rows, curr) => {
+      const userRoles = this.filteredProjectRoleTemplateBindings.reduce((rows, curr) => {
         const {
           userId, groupPrincipalId, roleTemplate, projectId
         } = curr;
@@ -211,7 +234,9 @@ export default {
         return rows;
       }, {});
 
-      return Object.values(userRoles);
+      // fakeRows must be added outside the reduce — they have no userId/groupPrincipalId
+      // and would be silently dropped if included in the reduce input.
+      return [...Object.values(userRoles), ...fakeRows];
     },
     canManageMembers() {
       return canViewClusterPermissionsEditor(this.$store);
diff --git a/shell/config/product/explorer.js b/shell/config/product/explorer.js
index 5e8b33e5091..fbb45b7b4ab 100644
--- a/shell/config/product/explorer.js
+++ b/shell/config/product/explorer.js
@@ -191,7 +191,7 @@ export function init(store) {
   configureType(MANAGEMENT.PROJECT_ROLE_TEMPLATE_BINDING, { isEditable: false, depaginate: dePaginateBindings });
   configureType(MANAGEMENT.PROJECT, { displayName: store.getters['i18n/t']('namespace.project.label') });
   configureType(NORMAN.CLUSTER_ROLE_TEMPLATE_BINDING, { depaginate: dePaginateNormanBindings });
-  configureType(NORMAN.PROJECT_ROLE_TEMPLATE_BINDING, { depaginate: dePaginateNormanBindings });
+  configureType(NORMAN.PROJECT_ROLE_TEMPLATE_BINDING, { depaginate: true });
   configureType(SNAPSHOT, { depaginate: true });
 
   configureType(SECRET, { showListMasthead: false });
diff --git a/shell/dialog/AddProjectMemberDialog.vue b/shell/dialog/AddProjectMemberDialog.vue
index f013750d411..eac555c0239 100644
--- a/shell/dialog/AddProjectMemberDialog.vue
+++ b/shell/dialog/AddProjectMemberDialog.vue
@@ -45,7 +45,8 @@ export default {
         principalId:     '',
         roleTemplateIds: []
       },
-      error: null
+      error:            null,
+      duplicateWarning: null
     };
   },
 
@@ -77,12 +78,35 @@ export default {
       this.close();
     },
 
+    // Returns the subset of roleTemplateIds that already exist for this principal+project.
+    existingRoleTemplateIds(principalProperty, principalId) {
+      const all = this.$store.getters['rancher/all'](NORMAN.PROJECT_ROLE_TEMPLATE_BINDING);
+
+      return this.member.roleTemplateIds.filter((roleTemplateId) => all.some(
+        (b) => b.projectId === this.projectId &&
+               b.roleTemplateId === roleTemplateId &&
+               b[principalProperty] === principalId
+      ));
+    },
+
     async createBindings() {
       const principalProperty = await this.principalProperty();
-      const promises = this.member.roleTemplateIds.map((roleTemplateId) => this.$store.dispatch(`rancher/create`, {
+      const principalId = this.member.principalId;
+      const duplicates = this.existingRoleTemplateIds(principalProperty, principalId);
+      const newRoleTemplateIds = this.member.roleTemplateIds.filter((id) => !duplicates.includes(id));
+
+      if (newRoleTemplateIds.length === 0) {
+        throw new Error(this.t('addProjectMemberDialog.duplicateRolesError'));
+      }
+
+      if (duplicates.length > 0) {
+        this.duplicateWarning = this.t('addProjectMemberDialog.duplicateRolesSkipped');
+      }
+
+      const promises = newRoleTemplateIds.map((roleTemplateId) => this.$store.dispatch(`rancher/create`, {
         type:                NORMAN.PROJECT_ROLE_TEMPLATE_BINDING,
         roleTemplateId,
-        [principalProperty]: this.member.principalId,
+        [principalProperty]: principalId,
         projectId:           this.projectId,
       }));
 
@@ -91,6 +115,7 @@ export default {
 
     saveBindings(btnCB) {
       this.error = null;
+      this.duplicateWarning = null;
       this.createBindings()
         .then((bindings) => {
           return Promise.all(bindings.map((b) => b.save()));
@@ -129,6 +154,12 @@ export default {
         >
           {{ error }}
         </Banner>
+        <Banner
+          v-if="duplicateWarning"
+          color="warning"
+        >
+          {{ duplicateWarning }}
+        </Banner>
         <ProjectMemberEditor
           v-model:value="member"
           :use-two-columns-for-custom="true"