Well, false alarm, you were right, it was the SIM card.... Short story, it is a pre-paid card, and I forgot to perform yearly checkup (in EU you need to verify yearly that you are the user of the...

Tried Tether.app from my Android phone, interestingly it says "All OK" and claims router is online! But, my android phone, on which Tether.app runs claims this WiFi has no internet access as well...

Same thing with "4G only". Attached some screenshots:

In Hungary 3G has been shut down since 2022 June 30. Since then, MR200 does not connect to 4G (using default "4G Preferred" setting), it gets WAN IP address and DNS IP addresses from operator, even...