In Cubase 12 (pro), while playing, at certain zoom levels the playhead/window moves slightly but erratically left/right.
But not when zoomed in a certain amount or zoomed all out.
I always use CTRL+mousewheel to zoom in/out.
For testing I tried zooming other ways = same behavior.
Let me know if I should try or investigate anything
Here’s a gif giving you an idea of it