Supervised Google account won't log in

Describe the bug
When I attempt to sign in with my personal Google account, it shows this error message: Please check your network.. Tap to retry.

This bug has begun appearing since I got device supervision via Google's family link on my new Google Pixel 4a (running Android 11: build RP1A.201005.006). I believe that device policy (another supervision app by google) must be using similar or the same code as another user has reported the same bug with that app.

To Reproduce
Steps to reproduce the behavior:

1. Sign in with a supervised account
2. See error

Expected behavior
I expect to be successfully signed in and not shown an error message.

Screenshots

System
Android Version: 11
Custom ROM: N/A: Stock Pixel Software

Additional context
The app I'm trying to use above is the latest version of YouTube Vanced. I have tested this with an excellent wifi connection.

Thanks in advance

The report names no source file, entry point, or test. Start by reproducing sign-in with a supervised Google account on Android 11 and compare it with an unsupervised account, using the reported network error as the observed failure. Done means identifying the affected authentication path and adding a verified fix or a focused regression test.