I have a secondary user account on my Pixel 8 Pro which I use for running sandboxed Google Play Services applications.
I was using Mullvad VPN (on both the Owner and the secondary account), when I ran out of devices on Mullvad as a result of adding a different device and I remotely deactivated that "seat" on the secondary user account. When I next switched to that account, the internet connection was broken.
I uninstalled Mullvad on that secondary account. No difference. Uninstalled it on the owner account too. No difference. Rebooted the device. No difference.
Something got broken as a result of that VPN deactivation and remains broken.
I was able to create a tertiary account and do the sandboxed setup and that works fine. I have retained the broken user account and the result is 100% reproducible. I can do whatever is required to try to extract logs or whatever else can be done to assist with debugging.