Lumin is on the QC list so I suspect your Qobuz software is an older version.
On Apple IOS, saw the exact same thing. Didn’t see an automated update so thought it wasn’t available. But when I went to the app update page on IOS for Qobuz, it showed an update was available. Performed on both iPad and iPhone fine. Mostly use the desktop 🖥️ version but they all work seamlessly. Sounds great.
Qobuz then logs you out on launch, you log back in and no more limited Airplay options. For IOS, the version is 8.0.0. For Android, I heard it’s 9.0 and there was a staggered global rollout. If for some reason, Qobuz didn’t log you out, I’d try logging out and back in. Last, check with Lumin if nothing works and see what they say.