After MT3000 upgrading from firmware 4.1.2 to 4.2.0 , the repeater mode to connect to 5GHz WiFi will fail all the time, only 2.4GHz will be working.
Which snapshot are you running. I can test later today.
I have tried 3 snapshots(20230107, 20230108, 20230109) so far, they all fail to connect to 5GHz WiFi in repeater mode.
I have Firmware 4.2.0 on my GL-MT3000 and have the opposite situation. Repeater mode connects to my Unifi U6-Pro 5GHz AX wifi access point, but not to its 2.4GHz AX wifi.
I will not install Snapshots that are released within every few days and have to be retested in case something else breaks.
I do not work for and I do not have formal association with GL.iNet.
I am not intended to install snapshot every few days, once it fails to connect to 5GHz Wi-fi in repeater mode you will want to try out more until it’s fixed.
Mine connected to the 2.4 channel of a mixed network. I’ll try to force it to 5 later when I have time to mess with it if it doesn’t come back up (or if I decide to set up the A1300)
For me, I only install up to Beta software, then it is for GL.iNet to fix problems that I report.
The preinstalled “stable” Firmware 4.1.2 is really only Beta, so I am okay with installing Firmware 4.2.0 Beta2 which is much better. Snapshots are for the development team and not for users to test.