Data loss / missing updates after tab suspension and edits on another device

Description

If a Whiteboard is open on a laptop and the browser tab becomes inactive due to sleep/energy saving, edits made on the same board from another device (e.g. phone) are not reflected on the laptop after wake-up. Reloading or reopening the board does not show the remote changes.

Steps to reproduce

1. Open a Whiteboard on a laptop.
2. Put the laptop to sleep or otherwise suspend the browser tab.
3. Open the same Whiteboard on another device and make changes. Then close the whiteboard on this device.
4. Wake the laptop and view the board. The changes will not appear. Even after closing and reopening the board, the changes will still not appear.

Expected behavior

After waking up or reloading, the laptop should fetch and display the latest board state, including edits from other devices.

Actual behavior

The laptop continues to show an outdated state and never displays the edits made on the other device.

Start by reproducing the sequence in the issue: suspend a laptop tab, edit the same Whiteboard from another device, then wake and reload the laptop. The issue names no files, tests, or entry points; done means the laptop fetches and displays the latest remote edits after waking or reopening.