Well, it appears to be that troubleshooting is indeed required judging by your issues.
When I refer to ‘run’, I mean run a command. To do that you generally need to be logged in to SSH unless you have another way to do it such as a serial console or maybe service that runs commands remotely.
So can you tell me whether or not the device’s configuration is saved after a proper Linux reboot?
If not, can you try changing your power supply out with something that provides 5V 1A and testing it then?
Disclaimer: I don’t work for GL-Inet, I just love their routers.