Hello,
Your problem is difficult to analyse without further details.
Can you connect to the repeater via its IP address?
Does the repeater use the same wifi network name (SSID) as your box or does it keep its own name? If the latter, try to connect using its own name, which, unless I'm mistaken, is printed on the packaging.
This link describes how to connect to a router from another manufacturer:
https://ch.avm.de/fr...What you are writing is far too unspecific. Just take a look at
https://monserveurnas.com/de... and realise for yourself that you have a "cheap device" as a router that is not compatible with top AVM devices.
A basic principle of all people who have the relevant knowledge (I am professionally familiar with your "subject matter" ...) actually only has one suggestion to make:
Only use network hardware from the same manufacturer ... and you will experience that almost all problems will disappear into thin air ...
Good luck with your "thinking" and making the right decision.
Michael Nagel
PD Dipl.-Ing. (FH)