Streaming - momentary frame freeze at video cut points

[NigelG]

we are streaming video sequences - and whatever I change occasionally there is a momentary freeze at a cut point. I've tried changing most options in the encoding doesn't make any difference. The rest of the time the stream is very good quality, it's only at cut points but not every cut just some.

These are cuts on the incoming video not cuts in OBS

I've tried software and hardware encoding.. nothing is over stressed or even close to it.

Any ideas>