1704313 - 'Manage Devices..." loads page whose main content is missing (no device list), link looks wrong

Status: RESOLVED DUPLICATE of bug 1703031

(Firefox :: Sync, defect)

Description

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

Firefox 89.0a1 20210410091448, 88.0b9, 87.0 on Windows 8.1

The "Manage Devices..." menu items in the Sync panel and the the Synced Tabs panel opens a page which doesn't show the device list (main area is empty).

Link is: https://accounts.firefox.com/settings/clients?context=fx_desktop_v3&entrypoint=syncedtabs-menupanel&uid=<auid>&email=<youremailaddress>#

Link should be (?): https://accounts.firefox.com/settings?context=fx_desktop_v3&entrypoint=fxa_discoverability_native&uid=<auid>&email=<youremailaddress>#connected-services

Steps to reproduce (Nightly):

1. In the app menu, click on the button to sign in to Sync.
2. Sign in with a Firefox account.
3. Enable synchronization of tabs in Preferences > Synchronization.
4. Repeat 1-3 in a different Firefox profile.
5. In the toolbar, click on the Sync button.
6. Click on the command to send the tab to a device (have a tab with content opened).
7. Click on "Manage Devices" in the submenu.

Actual result: Page loads but no content to manage devices.
Expected result: content to manage devices

Similar issue if the toolbar button with the synced tabs gets added and used.