Buffering problem

I have my Squeezebox Receiver / Controller combo for nearly 10 years. It worked flawless for years.

Recently I started having buffering issues with internet streams (Radio/Deezer).

For the last week my streams now buffer every 3-10 sec.

I also noticed issues when playing from my library, but not to the same extend as with internet streams. It just seems a bit slower to respond ...

I have tried everything I could think of ...

- rebooted router (no network issues) - I can play streams via softsqueeze without running into buffering issues.
- upgraded firmware (controller; not sure how to upgrade receiver - it is at 77).
- re-installed LMS 7.7.5
- upgraded LMS to 7.9.1
- reset receiver
- cleared preferences
- tweaked network buffer settings (default 3, changed to 10 /30)
- played streams via mysqueezebox

Not sure what else I could do ...

Any ideas?

Philipp