My understanding is that Tidal offers MQA/ Master recordings via the desktop app only at full resolution to those with MQA enabled DACs. For those without such DACs, software incorporated in the app allows those files to be played at up to 24/96 Res. However I've also been able to find recordings in Tidal's Android app that are labelled "hi-Res" and play at 24/48 (orange on the Mojo!) so I'm not quite sure what's going on.
I believe stock Android, for reasons best known to Google, upsamples automatically to 192 kHz (Mojo dark blue). If you want to play a digital music file via USB at it's native resolution, then you need to have a device/ install an app that bypasses the Android default. I recently started using USB Audio Player Pro which I bought from the PlayStore for $9.99. it supports streaming audio from Google musiic and Qobuz as well as Tidal.
Edit: To clarify, I unfortunately dropped my mojo/poly on a floor recently, and damaged the perspex housing the WiFi. it's in for repair, so I'm back to using the Mojo via USB, this time via Android rather than iOS. Trying to understand playing digital music via Android has been an education!