I might give up on the Radeon and buy an Nvidia.
I had the same problem until (by accident) I hooked up my AV receiver via HDMI to my 390 Nitro card, not using my Soundblaster Z.
Strange enough, this solved my problem with "Playback stopped because your graphics card driver is incompatible".
This is even the case, if I switch back to the SoundBlaster for audio output - doesn't make sense...
However, I have for months by now ongoing issues with stuttering MP4, AVi, any file formats in full screen. Sometimes removing/re-installing the driver does the trick, but it's back after a few days without any Windows updates and/or updates and changes on the AMD driver. Tried different driver versions, etc.
The problem is simple back out of the blue without any recognisable pattern
I'm on Windows 10 creators update now, but was the same before the update. Also PDVD 17 Ultra and 16 Ultra.