Hello everyone.
I recently purchased two themes (EC25-EU&KNe), and after updating to version 7.20.6 and flashing the modem to EC25EUGAR08A04M4G_A0.300, the GPS port stopped working. When I try to enable the GPS port, I get a “Port busy” message. However, commands such as AT+QGPS still work, and I can control the GPS using AT commands. But I would like everything to work stably.
Same situation at both of routers.
The usual suggesterd approach is to only change one thing at a time, changing two (RoS version and modem firmware) at the same time you cannot say if it is the one or the other causing the issue.
Which RoS version were you running before?
You can still try downgrading the device(s) to that version, if it works the firmware is not the culprit.
Generally speaking, 7.20. x is rather recent and the knot is not a very common device, so it is entirely possible (I would say more probable than firmware) that it is the RoS version.
If downgrading doesn't work, you will need to contact support and open a ticket (you should open one anyway, so that the good Mikrotik guys are aware of the issue, whilst some of them sometimes read forum posts, it is not given).