Disk Utility repair of APFS on M1: Fails in recovery mode, but fine in normal boot. Why?

Having upgraded to Sequoia (15.0.1) I wanted to clean up and check my 2021 M1 Max MBP SSD. Having backed-up to an external T.M. disk, I removed all local snapshots (using CCC) and ran Disk Utility on both my "Data" volume and its container, with no warnings or errors (see the first 2 screenshots).

I wanted to re-check the APFS container/volumes in Recovery Mode, so I booted into recovery. That's when the problems started...

The first problem I found was when I wished to run "First Aid" on the unmounted main Data volume. When I tried this I was asked for my password to unlock the encrypted volume. After entering it, Disk Utility hung forever trying to unlock the disk (see 3rd screenshot). This was repeatable behaviour, after power-off/re-enter recovery.

I then re-entered recovery and tried mounting the Data volume first. Doing so allowed me to start "First Aid" on the Data volume. Each time I ran First Aid I got the same warnings and an error message, followed by an apparent repair of the volume (see 4th screenshot).

I then tried to run "First Aid" on the container itself. Doing so causes Disk Utility to hang again (see 5th screenshot). Again, all these use-cases are repeatable.

So, my questions are: Can you please explain why this is happening (it never happened to me pre-Sequoia)? Is this something related to Sequoia that I should report to Apple? Should I trust my user-mode First Aid checks (which say "OK") or should I be worried?

I'd always considered Recovery Mode to be the trusted fallback for all tests and repairs. The fact that it is hanging is concerning to me.

BTW, the APFS layout is "standard" for a MBP (see 6th screenshot). Thank you for any and all help with this.