Kodi 17.0 – choppy/stuttering video playback on Mac mini Win 7

Hi guys

I’m getting choppy/stuttering video playback when “Settings > Player setting > Videos > Adjust display refresh rate” is enabled. The frame rate drops below 10fps and stays around 8 fps. The same videos play just fine when “Adjust display refresh rate” is off.
I’ve tried the usual options like “Delay after change of refresh rate”, “Sync playback to display”, “Allow hardware acceleration”, etc. with no luck.
The very same videos play just fine when running Kodi 17.0 under latest macOS on the very same computer.

Mac mini Server (Mid 2010)
Windows 7 Home Premium, SP1, latest updates

Any help is appreciated!