Step 1: Encounter Bug
Step 2: Open Mount Journal, and search for affected Mount:
Step Three: Dismount using button and re-mount using same button
This is incredibly annoying as I literally reported this on beta.
It’s been a thing since Dragonflight. 
Does the fix stick? If so, how long? Until next loadscreen, next login?
Ill have to do some experimenting for those answers.
Usually I just reload the UI and it fixes it.
nice fix, for some reason this is happening ALOT today for me. Used to just happen on the yak transmog mount, but now its happening on all flying mounts today 
finally someone with a “fix” been having this issua all week.
so the issue, is mounting via the Hotbar; that shoots the Camera 20ft above your Toon.
/Reload did nothing for me - but Mounting directly from the Warband works
I tried this fix on the Spring Butterfly, but it didn’t work.