Crash when logging it with Firefox Sync

I enter my password and after that, it just freezes and crashes. Is there something preventing my login?

All updates are installed and it's a new profile.

Terminal output only shows: Exiting due to channel error.

Start by reproducing the freeze and crash during Firefox Sync login in the new profile described in the issue, while collecting the terminal output. Investigate the source of the “Exiting due to channel error” message and identify the login path involved. Done means Firefox Sync login completes without freezing or crashing, with regression evidence.

Written by the indexing model from the issue text.