If you are running “R v1.15 stable” how would you account for the mismatch March 2023 Android 12 ? 
Did you last update the device to Google Official in March 2022 (tbh, I don’t know enough about build fingerprint to answer definitively) ?
Having looked at your List of partitions on your /e/ ROM (and the link with the hotdog firmware) I was thinking along these lines:
What partitions exist on an Official Google Android 13 (T) ROM
… and to what extent do they look like a near match with the /e/OS ROM
… does vendor (664 MB) exist
… if yes, do the two vendor (664 MB) share the same sha256sum ?
Pixels are easy to recover … so since
I think my ideas may be too much detail !
Maybe we need to be careful by the use of “dirty flashing” – upgrading from S → T without change of build type (not your case) would be a clean upgrade, I believe, Always take a full backup first !
Edit on a Samsung, this from about Phone > Android version this baseband version is a direct link to the preinstalled vendor firmware. Does your phone have an equivalent ?
