Oh yes, that's causing it. If all songs are marked "DONE", there is no song automatically selected to play next. Therefore the mini player will disappear after each song and this issue will occur. Open the History tab and tap on "Clear" to get rid of the DONE marker. With this step there will always be a song selected to play next and the error will not occur. Btw, you can disable the DONE marker in User Interface settings if you don't need it.
And iOS16.3 does not help with this issue.
Oh and regarding the XR12. Get the Mixing Station app. That's way better than the Behringer apps anyway and fully compatible with iOS16.