For use in TV / AV / Blueray apparently unsuitable

The positives: The switch is easy to operate. Ports are automatically detected and configured such that a signal (initially) is passed.

But after that it always comes back to crashes. The router behind the switch is then impossible to achieve for a long time and thus is also no Internet zV Sometime it goes then briefly again, then again not.
In addition, in the moments where he does the (Internet) connection is unbearably slow, almost modem speed from ancient times. In addition to the above mentioned devices as well as other tested eg laptop. Cables exchanged. Always the same phenomenon.
Perhaps it is not compatible with the router. (Compatibility issue?)
I have two boxes Fritz tested (6 and 7 version) or I caught a Monday device.
But if he goes back, unfortunately.