Choppy 4K ProRes playback QT

[4God]

Okay, so I'm on a 2017 15" MacBook Pro 3.1GHz 16GB Ram Radeon Pro 560 4GB graphics and the built in Intel HD 630 graphics. I'm connected to the 5K LG display and can't playback 4K ProRes smoothly. Weird. Does the same with just the internal display too. What's really weird is that if I switch to just the internal display on turn on graphics switching thereby using the Intel HD 630 graphics - it plays fine. What the heck? Help? My wife has the same machine and it does the same thing. (we're on Catalina 10.15.5)

 

[Fishrrman]

Have you tried any OTHER apps for playback, such as:
- IINA
- VLC
???

 

[4God]

VLC is a little better but still not as smooth as QT using the lame Intel HD graphics. Very frustrating.