diff --git a/tests/behavioral/helpers.ts b/tests/behavioral/helpers.ts
index f97aa70..30019df 100644
--- a/tests/behavioral/helpers.ts
+++ b/tests/behavioral/helpers.ts
@@ -36,7 +36,7 @@ export async function clickToggleOnWithRetry(
  * a sidebar and stays open between tests, so this is idempotent.
  */
 export async function openPickRandomUserPanel(modPage: Page): Promise<void> {
-  await modPage.page.waitForSelector(e.whiteboard, { timeout: ELEMENT_WAIT_LONGER_TIME });
+  await modPage.waitUntilInMeeting();
 
   if (await modPage.page.locator(e.pickRandomUserPanel).isVisible()) return;
 
diff --git a/tests/behavioral/multi-user.spec.ts b/tests/behavioral/multi-user.spec.ts
index e09be96..31b0c3f 100644
--- a/tests/behavioral/multi-user.spec.ts
+++ b/tests/behavioral/multi-user.spec.ts
@@ -29,11 +29,11 @@ const setPluginUrl = (url: string) => { pluginUrl = url; };
 const getPluginUrl = () => pluginUrl;
 
 /**
- * Wait for the attendee's page to finish loading the whiteboard.
+ * Wait for the attendee's client to finish loading.
  * This ensures the attendee is fully in the meeting before the presenter picks.
  */
 async function waitForAttendeeMeeting(attendeePage: Page): Promise<void> {
-  await attendeePage.page.waitForSelector(e.whiteboard, { timeout: ELEMENT_WAIT_LONGER_TIME });
+  await attendeePage.waitUntilInMeeting();
 }
 
 /**
@@ -99,6 +99,7 @@ test.describe('Pick Random User Plugin - Behavioural (multi-user)', () => {
     if (attendeePage.settings?.autoJoinAudioModal) {
       await attendeePage.closeAudioModal();
     }
+    await attendeePage.waitUntilInMeeting();
     await attendeeRawPage.addStyleTag({
       content: "body { font-family: 'Liberation Sans', Arial, sans-serif; }",
     });
@@ -338,6 +339,7 @@ test.describe('Pick Random User Plugin - Behavioural (countdown and close-preven
     if (attendeePage.settings?.autoJoinAudioModal) {
       await attendeePage.closeAudioModal();
     }
+    await attendeePage.waitUntilInMeeting();
     await attendeeRawPage.addStyleTag({
       content: "body { font-family: 'Liberation Sans', Arial, sans-serif; }",
     });
diff --git a/tests/core/sessionPage.ts b/tests/core/sessionPage.ts
index 555e127..8e560c9 100644
--- a/tests/core/sessionPage.ts
+++ b/tests/core/sessionPage.ts
@@ -83,6 +83,7 @@ export class SessionPage {
       this.settings = await generateSettingsData(this.page);
       const autoJoinAudioModal = this.settings?.autoJoinAudioModal;
       if (shouldCloseAudioModal && autoJoinAudioModal) await this.closeAudioModal();
+      await this.waitUntilInMeeting();
     }
     // overwrite for font used in CI
     await this.page.addStyleTag({
@@ -132,4 +133,22 @@ export class SessionPage {
     await this.hasElement(e.audioModal, 'should display the audio modal', ELEMENT_WAIT_EXTRA_LONG_TIME);
     await this.page.click(e.closeModal);
   }
+
+  /**
+   * Wait until the in-session client is ready to be driven.
+   *
+   * Deliberately keyed on the apps gallery button rather than on the whiteboard: this
+   * plugin is reached through the apps gallery, and the button renders for moderators and
+   * viewers alike regardless of what the media area is showing. The whiteboard is a poor
+   * readiness signal here — a server that sets layout.hidePresentationOnJoin
+   * joins users with the presentation minimized,
+   * and the canvas is then not in the DOM at all, so waiting for it can only time out.
+   */
+  async waitUntilInMeeting(timeout = ELEMENT_WAIT_EXTRA_LONG_TIME) {
+    await this.hasElement(
+      e.appsGallerySidebarButton,
+      'should display the apps gallery button once the client is in the meeting',
+      timeout,
+    );
+  }
 }
diff --git a/tests/structural/test.spec.ts b/tests/structural/test.spec.ts
index d0424ad..7b2bf2c 100644
--- a/tests/structural/test.spec.ts
+++ b/tests/structural/test.spec.ts
@@ -76,7 +76,7 @@ test.describe('Pick Random User Plugin - Structural', () => {
   }
 
   test('should list "Pick random user" in the apps gallery for a presenter', async (): Promise<void> => {
-    await modPage.page.waitForSelector(e.whiteboard, { timeout: ELEMENT_WAIT_LONGER_TIME });
+    await modPage.waitUntilInMeeting();
     await modPage.page.click(e.appsGallerySidebarButton);
     await modPage.hasElement(
       e.pickRandomUserAppsGalleryItem,