We have stage shows recorded using the Blackmagic Duplicator 4K unit and I edit in Adobe Premiere Pro CC 2019 (13.0.2). The files recorded by the Blackmagic Duplicator are H.264 1080 with a data rate of 7.09 Mbit/s.
Playback in PP 2019 is glitchy (see screen shot). The file plays back with no problems in QuickTime. I did not have this problem until I upgraded to PP 2019. When I open the exact same files in PP 2018 (still installed on the same system), I have no problem.
When I open files recorded a year ago on the same Blackmagic unit, I see the same results. Good in PP 2018. No good in PP 2019.
As best that I can tell, the problem is with Premiere Pro 2019.
I am editing on a iMacPro (2017) with a 3GHz Intel Xeon W processor, 32GB 2666 MHz DDR4 memory, and a graphics card of Radeon Pro Vega 64 16368 MB.