Well don’t take it as the answer…it’s possible my animation is moving slow enough that it’s not noticeable.
I have been doing a lot of rendering this week with the same issue…only real solution is to adjust the time line sequence for about 10 frames including the missing one (s) and re-render.
It’s a pain but it works. But I can confirm the error (missing frames) happens every time and I’ve tried both exr and png with alpha when I have a sequence over 180 frames.