Signing in to sync containers causes account to become unverified

[flcdrg]

Description

On a fresh install of Firefox, after I enable syncing with Containers, my previously signed in account now has 'unverified' and asks me to re-verify it.

Steps to reproduce

1. Fresh install of Firefox on Windows
2. Sign in with Firefox account (including 2FA)
3. View Settings page and there is no warning about account being unverified
4. Click on Containers icon in toolbar
5. Sign in again to enable Container syncing (including 2FA)
6. Containers are now syncing, but Firefox reports on Settings page that account is unverified

Expected result

Signing into Container sync should not cause account to change to unverified

Actual result

Need to click on Verify Account to re-verify the account again!

Environment

Windows 11, Firefox 137.0.2 (64-bit)

┆Issue is synchronized with this Jira Task