Thank you for taking the time explaining what the issue is about as I’m sure there are many people not aware of how this works inside the simulator.
As a matter of fact, you might want to note this is a very old bug well known since FS9.
For example, a quick search and you find posts about this dating back from 2004!
https://www.avsim.com/forums/topic/40715-obs-needle-moves-10-degrees-at-a-time/
More recent posts (2010):
https://www.avsim.com/forums/topic/472414-heading-bug-only-moves-in-10-degree-increments/
https://www.avsim.com/forums/topic/39580-instrument-increase-problem/