It appears the frame rate of your QT media is 23.976, correct?
What is the frame rate of your sequence?
Thanks for the quick response!
You are correct, my media is 23.976 and I matched the sequence settings to this when adding the clips to the timeline.
So... you are certain your sequence frame rate is 23.976.
I see a green 'previews rendered' line above your clips...
have you applied an effect that required rendering?
Yes. I checked the sequence setting and the timebase is 23.976.
I applied a warp stablization effect to these clips
I was skeptical but somehow turning the opacity of both clips to 0% then back to 100% and rendering seems to have fixed the issue!
Admittedly a weird fix... glad it worked.