[FernetMenta]

Just as a note. I created an issue on the kodi github, but so far noting really happened.
I would guess that maybe also beside of my bug report the issue could vanish in further kodi updates. Is there something one should look out for to give it a try?
I decided to install 1027 again as long as there is no update, because it gives me a lot less trouble.

Yes, issue #14977.

Another user has created issue #15002 which mentions 2 mouse pointers/cursors, and in it I think fernetmenta may be referring to your issue. Still not sure why the issue you have reported would start with build #1028.    

 Because this was merged Oct. 27th: https://github.com/xbmc/xbmc/pull/14701

EDIT: the solution is simple: just whitelist the refresh rates you really need. In general those are only 23.976, 24, 50, 59.94, 60