I can currently only try this with a Seaboard Rise, but it works quite well there, using Bitwig 5.1 beta 6 and the Bazille VST3 MPE beta.
A while ago we also tested MPE with the Linnstrument in Bitwig and it worked as well.
Did you set everything up as suggested in the first post of this thread?
Have you tried starting host playback to see if that maybe resets some things and fixes the problem?