When not connected to WiFi though (regular 4G connection), Jolla store isn’t working. And system also can’t check for updates.
I remember also before running system update it complained something about ofono-* package possibly causing some problem, but I ignored that. Not sure it it’s relevant.
I think I found another symptom. In my case in Cellular Network settings, it shows constant connecting / limited connectivity back and forth. So possibly something got messed up on the updated related the network after all.
OK, I think I found the culprit. I switched my network from dual to IPv6 and now it’s connecting stably. Not sure why it used to work before but became a problem after the update.