I have the same problem as described by hatter. I have only Swisscom hardware. But looking at the list of manufacturers and the replacements of routers and tv boxes I have had over the years there is no joy.
And yes, restarting the tv box solves the playback problem - for a short while. Basically, one cannot use playback on a regular basis.
And yes, it was not a problem about a year ago.
So I have to ask myself: What is the added value Swisscom provides for the extra cost when compared to the competition?
To switch boxes on and off or replug all ethernet cables after a router update, the lack of documentation of a host of Swisscom functions across the board and the inability or unwillingness to improve the services to the standard one was used to all amounts to a mediocre overpriced service.