I am having the same issue. This only seems to have happened since the update that I just did. Tidal works fine from Roon but Qobuz does not. Qobuz works fine from the NAIM app, just not Roon. I have tried logging out of Qobuz and logging back in but the Qobuz tracks never play. I have a NAIM NDX2 with latest firmware.
Glad its not just me. (Not that I use tidal, just Qobuz)
As I’m on the free 14 day trial, and 4 days in this is not allowing to me asses the app. Right now, I thinking of just using the Naim app to drive Qobuz and my NAS library. Apart from thefancy upscaling, I only have one end point ( my ND5XS2) so am struggling to (yet) see the appeal.