Hello Roger515
When you log on to the repeater, you can read out the information under Settings Wifi / Radio Channel. There in the menu you can see the whole network width. This way you can estimate if someone is trying to reach you or if the frequency band is simply too full and you should change it.

In addition, you can set up a push message service so that you receive precise information by e-mail in the event of an incident. You can also set up to receive a report periodically with a list of incidents.

If you don't know the IP of the repeater in the network, you can link to it by entering this address.

http://fritz.repeater/

Please carry out the software update. Under System / Update

P.S.: As I understood you, you have one or even two repeaters in brigde mode. You may then only have half the bandwidth throughput. If possible, try to set up a LAN bridge with the repeater. The Fritz!Wan can do this, just use the same SSID (network name) and password. I meant the channel can be different.

I once had a similar problem. It helped me to change the WLAN Chanel of the access point and to reset the repeater to factory settings and set it up again.