Your Mu-Sos are not “bricked”, they are fine and all functions should still work, barring of course iRadio. What has happened is that vTuner who provide the iRadio service have ceased providing their service, so your Mu-Sos cannot currently connect to it.
Naim have been working on a contingency for just such a situation for a while now and today stated that there will be an over-the-air update via the APP for your Mu-Sos that will allow them to use Naim’s new in-house Internet Radio service. They reckon this should be available by February 14th.
In the meantime, I have posted up some suggestions for alternative ways to get Internet radio to your Mu-Sos using other devices. You can see those on this thread here: