Slomo jitter after render

Slomo jitter on 25fps timeline Resolve 17.2.2 build 4

I have two 47.952 and two 50fps DJI Phantom 4 Pro shots on a 25 fps timeline with other shots filmed at 25fps. They run smoothly but the slomo shots are jittery - but only when rendered. On the timeline they are buttery smooth. I've made MP4 versions and used a thumb drive and a DVD disk and played back on a TV. That's when the problem shows up.

BTW - Im still on the learning curve of DR.

Resolve 17.2.2 Master Settings are - HD 1920_1080 Video monitoring - HD 1080p 25 Video bit depth 8 bit Optimized Media and Render Cache - Proxy media rez - Original Proxy media format - H.264 Optimized media rez - Original Optimized media format - DNxHR HQ Render cache format - DNxHR HQ

Frame Interpolation - Realtime process - Nearest (also tried Optical flow) Motion estimation mode - Standard faster Motion range - Medium

Tried to attach txt files about the shots - not allowed??

Can anyone advise what might help sort out this issue. Many thx