Help with MESH Repeater.

Dear Community,

I have a DOCSIS main router which connects to the internet and it does not support MESH network capabilities. Using LAN1, I connect my Router-1 to the DOCSIS station and then create WLAN MESH network. I connect my Router-2 to this WLAN MESH network. But the problem is time to time my DOCSIS station restarts which kills my Router-2's internet connectivity. Everything is working but the Router-2 does not have an internet connection anymore even though the user interface for Router-2 says it is connected to the internet.

Please tell me if there is a solution to my problem. I would be very much thankful.

My DOCSIS station is https://zuhauseplus.vodafone.de/internet-telefon/kabel/router-optionen/

My Router -1 and Router -2 is Fritz!Box 7490.

Thank you