Tabs and Tab Groups missing after leaving sync chain

Brave Browser Sync
1

Description of the issue:
After leaving a sync chain, some of my tabs and tab groups missing/closed/disappeared without a trace.

I have 100+ tabs in several groups, and after leaving sync chain, I’m left with 50+ tabs and fewer groups. most of them is bookmarked so I’m not worry about that, but the newer one still not bookmarked.

Steps to Reproduce (add as many as necessary):

  1. Settings → Sync
  2. Click trash icon next to This device
  3. Leaving sync chain
  4. Notice that some tabs and tab groups disappeared

Reproduces how often:
once

Brave Version(See the About Brave page in the main menu):
Beta 1.90.99

Type of devices currently running on the Sync chain in question:
Android, Xiaomi Poco C65

Additional Information:
Looks like it’s only affect tabs and tab groups, as bookmarks (probably, as I have thousands of bookmarks and not sure if some is missing), passwords, and history still there.

ideally leaving sync chain should not delete the data on the device right? as this device is the latest one added, the most active, and the one currently in use. The others are dead for months now so all the missing tabs should belong to this devices.

and I’m leaving sync chain to test Closed tabs reopening without input and see if it’s related to sync as the linked issue started to bothering me.

TIA