I have a Lenovo Tab4 10 Plus, running an upgraded lineage OS for Android 9 and a Tab4 8 Plus running standard Android 8.1
Everything runs fine on the 8 Plus for both cycling (Tacx Neo) and Running (MyRun).
On the 10 Plus, cycling works fine, however, while it connects to the MyRun and shows it connected successfully, it does not pass through speed or running cadence. It just shows as properly connected but no data comes through.
Obviously, since this is running a non-standard image there is little to investigate, however, it does seem strange that the cycling part works and the it is just the running that is strange, The bluetooth connection would be the difficult bit I would have thought.