You need to use cable specifically designed for SDI. RG59 essentially only defines the impedance and capacitance of the cable, not the return loss and attenuation characteristics. You can use reference charts from cable manufacturers like Belden and Gepco to select the right cable for your situation.
Have you tried resetting preferences and/or plugin cache?
Press Alt (Windows) or Option (Mac OS) while launching Premiere Pro.
You can release the Alt key or Option key when the splash screen
To reset preferences and plug-in cache at the same time, hold down
Shift-Alt (Windows) or Shift-Option (Mac OS) while the application is
Edit lists is a feature, that allows you to edit videos without re-encoding. For example, you want to remove a scene, make your edit points which are written into the container file. A video player reads those instructions and just such parts of the video. However, not many players seem to support that feature, nor does Instagram, so simply don't use it. I ...
The easiest way is to retime remaining frames using setpts.
ffmpeg -i in.mp4 -vf "blackframe=amount=0:threshold=92, metadata=select:key='lavfi.blackframe.pblack':value=45:function=less,setpts=N/FR/TB" -vsync 0 outz.mp4