I am a long term Fritz!Box user. I have always been happy to install beta firmware accepting that most of the issues will have been solved with the first to be deployed German language version. Sadly, this was not the case with the beta firmware released late last year. AVM could see nothing out of the ordinary when they reviewed the box's diagnostics. Yesterday, I installed the latest beta firmware release.
My Fritz!Box has finally got its mojo back. It was either a problem with the firmware or the install as the firmware recovery tool consistently failed to identify the old beta. I was worried that I might have an expensive brick on my hands.