Then, use Alt+1 to rotate left, Alt+3 to rotate right, 5 to reset. Note, that the numbers correspond to the numpad ones.
You have accidentally enabled D3D Fullscreen, go to Options → Output and disable the D3D Fullscreen checkbox.
The video display is experiencing a synchronisation issue, try enabling V-Sync by pressing V. If you have more than one monitor connected make sure you extend the screen instead of duplicating it.
Hardware acceleration is most likely not working correctly. Try going to Options → Internal Filters, right-click the list on the right and click “Disable DXVA filters” and then reload the video (Ctrl+E or manually). If this does not solve your issue, and your video plays correctly in other video players then please make a bug report.
Supporting these new platforms require many changes and this is simply not possible for us in the near future, with the current manpower.