I experience 3 issues after Android 13 update:
Roaming: I live on the border with Slovenia, and roaming just stopped working. No data network, phone network connection working. Data is only reconnected if I go back to Italy, though I need to restart the phone.
I didn’t care that much until I traveled to Belgium: a week offline, except for the occasional wi-fi! A nighmare.
Yesterday I tried moving my SIM to another phone, and went to Slovenia, and it worked! So I know the problem is my loved Fairphone3, or a combination of that with my operator.
Fingerprint: some apps seem unable to read my fingerprint. This is particularly problematic for my home banking. Last time I was abroad I was totally unable to access home-banking not only because of the internet access (see above), but because a 2-steps recognition system demands fingerpint OR a code sent via text message. But I did NOT receive text messages from Italy abroad, because of my operator.
Blank screen: sometimes the screen becomes totally dark, the phone seems not to work anymore. I have to force restart and then I am placed back where I was (same windows open a.s.o.) as if I hadn’t rebooted. Might be a screen issue, it does not happen regularly, and I had receive some Graphic UI notices months ago that I never solved.
I am considering what to do next, moving out of fairphone is one of the options