https://bugs.winehq.org/show_bug.cgi?id=41909
--- Comment #5 from Johannes wine@sagagames.de --- (In reply to Nikolay Sivov from comment #4)
Actually, I don't think it's supposed to work like you expect it to. I did some more testing and it's clearly checking previous position and if it's the same thumb does not move. Could you attach your test application here, so I can test it myself?
The real-world example where this is taken from is OpenMPT: https://openmpt.org/download
Run the application, go to File -> New -> OpenMPT Module, then View -> Song Properties, then click "Configure Swing". You will notice that all sliders are centered on Windows (their value is 0 in a -500...500 range), but on Wine they are all on the left.
OpenMPT is an MFC application but I checked that MFC's wrappers don't do anything else apart from these SendMessage calls.
If this is too complicated to debug, I can try whipping together a minimal example.