Interesting problem, Guido.
I've only used Support a couple of times over the years, it may take them several days to get back to you but they will. Let us know what happens.
My only comment about this is Biab is built specifically to not play exactly what you put into either the Stylemaker or just the chords on the chord grid. This is why there's all those options to allow some control over that. The point of Biab is to try to simulate a band of real live players. Real players won't play a given song exactly the same way every time, there's always some variation and this is what gives Biab a certain level of live feel. Every time you hit play, Biab will regenerate the tracks and each time will be a bit different from the last. If you hear a version you really like, hitting replay will play it again without regenerating it but simply saving the song won't help, when you go into that song again it will regenerate it again. If you want it to stay like that you have to freeze the tracks, then save it.
I don't know if this is relevant to your problem with the Stylemaker or if this is indeed a bug.

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.