This could be helpful for fellow owners of NAD C368 (or other models) amplifiers with the BluOS MDC2 module:
I was prompted to update the BluOS firmware the other day - as usual, this went seemingly without a hitch. However, today, when I attempted to stream using Roon, nothing happened and the amp had disappeared from the list of Roon-ready devices. In its place was something called “MDC3” with a message saying that it was not Roon certified. Slight panic ensued because BluOS don’t make reverting to earlier firmware easy.
However, a bit of Googling brought up a previous post here which described a similar problem and a suggested solution - basically, hard resetting the amp remakes the connection to the MDC BluOS module and enables Roon to recognise the amp and module as Roon-ready. This worked a treat.
If you’ve had a similar experience (and I understand from the older post that there are hundreds of C368 / MDC2 owners using Roon), this might be of interest.