What logs can I look at to see why my Spitz downgrades to a worse 4G from 5G signal?

Router
1

If I reboot the gateway, it’ll connect to 5G, which actually has better signal qualities, but after a while, it jumps down to 4G, which is actually worse signal strength. Running 4.8.3. I know there is an AT command to force the modem to 5G, but if I do that, it just loses connection entirely until reboot.

3

This requires checking the modem log. However you can first run the following commands to view network details.

AT+QENG="servingcell"
AT+QCAINFO
AT+QNETRC?