For me it only works the other way round, selecting a HALion5 track in the project window will switch the track selection in the VST.
This selection behavior was first introduced in 7.5 I think, and only works both ways, as intended and expected, with GA SE and GA4. HALion5 was released just before 7.5, so the selection behavior is only partly impelmented in this VST.
Personally I would not mind if we could change the behavior on user preference level, because I think Cubase’s way (project to VST) makes more sense.
I noticed in Studio One it’s very annoying when the project’s track selection/view always follows Halion 5. Sometimes you just want to make a small adjustment to a parameter in Halion 5 while an entirely different track is in view. The result is the track attached to Halion is scrolled in to view while that isn’t necessary because you don’t want to edit the track content.