And the best AVM products, ... the service hotline. Within 20 Minten all problems were eliminated. I had made adjustments in my Fritz box, the disabled, the Quick Installation. Competent you are every step was resolved with my single went through until the fault. This is no mean feat on the basis of remote diagnostics!
Conclusion: One can only further! In a 3-level house "Repeater FRITZ! 310" is the value of gold. :)