diff --git a/src/hooks/useUpdateURLCatalogParam.ts b/src/hooks/useUpdateURLCatalogParam.ts
index e8e8ef2b..1477aa60 100644
--- a/src/hooks/useUpdateURLCatalogParam.ts
+++ b/src/hooks/useUpdateURLCatalogParam.ts
@@ -7,6 +7,14 @@ import { useExploreState } from "./useExploreState";
  */
 export const useUpdateURLCatalogParams = (): void => {
   const { exploreState } = useExploreState();
+  // `pathname` is intentionally still read from useRouter() here so it stays as
+  // the route pattern (e.g. `/[entityListType]/[entityId]`). The pattern is
+  // required by the Router.replace({ pathname, query }) call below — Next.js
+  // interpolates dynamic-param keys (entityListType, entityId, …) out of the
+  // query into the path. usePathname() would return the already-resolved URL,
+  // which on dynamic routes would leave those keys in the query string. The
+  // migration to usePathname()/router.replace() is tracked in #930 and #931
+  // and will be done together with the Router.replace refactor.
   const { basePath, pathname, query } = useRouter();
   const { catalogState } = exploreState;
 
diff --git a/src/views/ExportMethodView/exportMethodView.tsx b/src/views/ExportMethodView/exportMethodView.tsx
index 428db4c8..92272e98 100644
--- a/src/views/ExportMethodView/exportMethodView.tsx
+++ b/src/views/ExportMethodView/exportMethodView.tsx
@@ -1,4 +1,4 @@
-import { useRouter } from "next/router";
+import { usePathname } from "next/navigation";
 import { JSX } from "react";
 import { ComponentCreator } from "../../components/ComponentCreator/ComponentCreator";
 import { BackPageView } from "../../components/Layout/components/BackPage/backPageView";
@@ -8,7 +8,7 @@ import { useUpdateURLSearchParams } from "../../hooks/useUpdateURLSearchParams";
 
 export const ExportMethodView = (): JSX.Element => {
   useUpdateURLSearchParams();
-  const { pathname } = useRouter();
+  const pathname = usePathname() ?? "";
   const { exportMethods, tabs } = useExportConfig();
   const { sideColumn } = tabs[0];
   const { mainColumn, top } =
diff --git a/tests/stateSyncManager_utils.test.ts b/tests/stateSyncManager_utils.test.ts
new file mode 100644
index 00000000..e0d3ee97
--- /dev/null
+++ b/tests/stateSyncManager_utils.test.ts
@@ -0,0 +1,138 @@
+import {
+  hasParams,
+  isSynced,
+  stringifyQuery,
+  wasPop,
+} from "../src/hooks/stateSyncManager/hooks/UseStateSync/utils";
+import type { NextHistoryState } from "../src/services/beforePopState/types";
+
+/**
+ * Builds a minimal NextHistoryState for tests.
+ * @param url - The href stored by Next.js in history state (the route
+ *   pattern on dynamic routes, e.g. `/[entityListType]/[entityId]`; the same
+ *   string as the URL on static routes).
+ * @param as - The resolved URL shown to the user. Defaults to `url` for
+ *   static-route cases where the two are identical.
+ * @returns NextHistoryState with the given fields and no-op options.
+ */
+function buildHistoryState(url: string, as: string = url): NextHistoryState {
+  return { as, options: {}, url };
+}
+
+describe("wasPop", () => {
+  it("returns false when nextHistoryState is undefined", () => {
+    expect(wasPop("", "/projects", undefined)).toBe(false);
+  });
+
+  it("returns true when pathname matches the path component of the history URL", () => {
+    expect(wasPop("", "/projects", buildHistoryState("/projects"))).toBe(true);
+  });
+
+  it("strips the query string off the history URL before comparing", () => {
+    expect(
+      wasPop("", "/projects", buildHistoryState("/projects?filter=foo")),
+    ).toBe(true);
+  });
+
+  it("returns false when pathname does not match", () => {
+    expect(wasPop("", "/projects", buildHistoryState("/files"))).toBe(false);
+  });
+
+  it("defaults basePath to empty string when not provided", () => {
+    expect(wasPop(undefined, "/projects", buildHistoryState("/projects"))).toBe(
+      true,
+    );
+  });
+
+  it("prepends basePath to pathname before comparing", () => {
+    expect(
+      wasPop("/data", "/projects", buildHistoryState("/data/projects")),
+    ).toBe(true);
+  });
+
+  it("returns false when basePath is set but missing from the history URL", () => {
+    expect(wasPop("/data", "/projects", buildHistoryState("/projects"))).toBe(
+      false,
+    );
+  });
+
+  // Documents the contract: nextHistoryState.url is the href stored by
+  // Next.js — the route pattern on dynamic routes, the static URL on static
+  // routes. `pathname` must be in the same form for the comparison to match.
+  it("matches on a dynamic route when both sides are the route pattern", () => {
+    expect(
+      wasPop(
+        "",
+        "/[entityListType]/[entityId]",
+        buildHistoryState(
+          "/[entityListType]/[entityId]?filter=foo",
+          "/anvil-cmg/abc-123?filter=foo",
+        ),
+      ),
+    ).toBe(true);
+  });
+
+  it("does not match when pathname is the resolved URL but history url is the route pattern", () => {
+    expect(
+      wasPop(
+        "",
+        "/anvil-cmg/abc-123",
+        buildHistoryState("/[entityListType]/[entityId]", "/anvil-cmg/abc-123"),
+      ),
+    ).toBe(false);
+  });
+});
+
+describe("hasParams", () => {
+  it("returns true when any param key has a defined value in the query", () => {
+    expect(hasParams({ filter: "foo" }, ["filter"])).toBe(true);
+  });
+
+  it("returns true when at least one of multiple param keys is present", () => {
+    expect(hasParams({ sort: "asc" }, ["filter", "sort"])).toBe(true);
+  });
+
+  it("returns false when none of the param keys are in the query", () => {
+    expect(hasParams({ other: "x" }, ["filter", "sort"])).toBe(false);
+  });
+
+  it("returns false for an empty paramKeys list", () => {
+    expect(hasParams({ filter: "foo" }, [])).toBe(false);
+  });
+
+  it("returns false when a param key is present but undefined", () => {
+    expect(hasParams({ filter: undefined }, ["filter"])).toBe(false);
+  });
+});
+
+describe("isSynced", () => {
+  it("returns true for two empty queries", () => {
+    expect(isSynced({}, {})).toBe(true);
+  });
+
+  it("returns true when queries have the same keys/values in different order", () => {
+    // eslint-disable-next-line sort-keys -- intentionally unsorted to exercise insertion-order independence.
+    expect(isSynced({ a: "1", b: "2" }, { b: "2", a: "1" })).toBe(true);
+  });
+
+  it("returns false when queries differ in value", () => {
+    expect(isSynced({ a: "1" }, { a: "2" })).toBe(false);
+  });
+
+  it("returns false when one query has extra keys", () => {
+    expect(isSynced({ a: "1" }, { a: "1", b: "2" })).toBe(false);
+  });
+});
+
+describe("stringifyQuery", () => {
+  it("produces identical output regardless of insertion order", () => {
+    expect(stringifyQuery({ a: "1", b: "2" })).toBe(
+      // eslint-disable-next-line sort-keys -- intentionally unsorted to exercise insertion-order independence.
+      stringifyQuery({ b: "2", a: "1" }),
+    );
+  });
+
+  it("produces empty-object JSON for an empty query", () => {
+    expect(stringifyQuery({})).toBe("{}");
+  });
+});