Geofencing triggers don't work after changing phone from S10 to Pixel 7 Pro

A completely separate issue, but since you mentioned location modes…

Some Routines that set location modes broke for many people on 15 November 2023, regardless of the type of phone they are using. Even if the routines had previously worked fine. So that might at least have interfered with your testing.

The good news is that problem appears to have been fixed on 18 November 2023, although in a few cases people had to recreate the routines they had been using.

See:

Location Mode Changes Failing (15 Nov 2023)