Output File shows ungraded/graded one frame apart

Please see attached.
The output files after final grade have a pattern like this:
Frame 1: Ungraded.
Frame 2: Graded.
Other files have a pattern like this:
F1: Ungraded.
F2/3: Graded.
F4-6: Versions of an earlier, unfinished grade.
This stroboscopic affect appears on the following cameras:
FS7, A7S, GP7.
It does not appear on this camera:
DJI Mavic Pro
FPS for Timeline: 23.98
Thanks.
The output files after final grade have a pattern like this:
Frame 1: Ungraded.
Frame 2: Graded.
Other files have a pattern like this:
F1: Ungraded.
F2/3: Graded.
F4-6: Versions of an earlier, unfinished grade.
This stroboscopic affect appears on the following cameras:
FS7, A7S, GP7.
It does not appear on this camera:
DJI Mavic Pro
FPS for Timeline: 23.98
Thanks.