Unfortunately I cannot add a solution.. but I can join in with the same problem
However, I don’t do lot of “traffic-intensiv” things.. the wifi connection is still running and devices are connected, but the internet does not work - sometimes up to 1 min.. I can quickly disconnect and reconnect and it immediately works again.
My Connectbox (the new 1Gbps) shows the same error message as you posted. Even after Reset of the box. So it’s not a box configuration issue - I also believe it’s either a faulty unit, or as it seems maybe a firmware issue?
Phone support checked location and recommended moving it away from the wall - not a long term solution because having the box in the middle of the room is not an option.
Also, it’s not a solution as it still drops and shows the error in the backend.
Getting my own router is no option for me, as the box is sold as “WIFI” capable it should also do so - and I don’t want second device in my living room. And last, my old Connextbox worked fine for 3.5 years.
So - as said, no solution but only frustration. If you have any update, please let me know.