''Salut! ''
Ok I made a short video that shows the problem.
I used one of your demo song freshly loaded. Also, I just installed the non portable version and it does not fix the bug, I also restarted my computer, no luck.
As you can see on the video, the pattern position marker is moving slower than the actual playback and the piano roll marker. I am using a Behringer UCA200 usb audio interface for my audio output.