I had a pretty strange experience this winter as well. MCU kept crashing anytime I tried to do the recalibration the night that I swapped sets, so I figured some config file with the addresses of the TPMS on the winter set was corrupt. I made a service appointment, and the following day, without any intervention it gave me the new tire size detected prompt. The night before I did the usual resetting of everything, restarting, changing sizes, recalibrating, driving around my neighborhood at various speeds, etc.
As crazy as it sounds, considering that I set up an appointment using the app, and posted pics of the error messages ("Tire pressure monitoring system fault - Sensors unable to measure tire pressure" and all the other related TPMS error messages people have posted), I'm imagining that someone just remotely wiped a file that had a corrupt config in it, and the next time I started driving in the morning, it did the normal checks. Maybe something else triggered it, but I'd like to believe that they saved themselves a service center visit with some remote diagnostics.