I have now find a way to see the wifi-channel. The phone use ch 13, so this is maybe the problem.
Is there a possibility to bring the router to work also with this channel?
I found this: GL-MT300N-V2 unable to be repeater for wifi network channel 13 but I don’t know how “You can ssh to the router and change the wifi settings” works.
Can you please help me again?
Best regards