Yes I was about to suggest rebooting the router when I saw timjoebill's reply. In my experience there is almost no situation where reinstalling the Naim app is necessary. The Naim app is very stable now and the 272 is too, so the issue is almost always a networking issue. Rebooting the router is one fix to try and a more long term fix is to put a cheap switch like a GS105, to which you connect everything and just have one cable back to the router. That change sorted out my occasional networking issues in one go.
Going back to your muting problem, if you are still running the firmware which was in the 272 when it was delivered from the factory, then I think the suggestion someone made of a faulty logo/mute switch is worth following up. If someone has done a firmware update on the 272, then it could be worth resetting the 272 to factory settings because the firmware updates mostly don't do this and Naim recommend a factory reset. Occasionally odd and inexplicable issues get reported in the forum which get sorted by a factory reset.
Good luck.
best
David
