%q converter jumps back and forth in an event?

[sroller]

I'm outputting a series of pictures in case of an event, copy the sequence from a Pi 3 B+ to another computer where I use ffmpeg to create a daily movie.
I'm using the %q placeholder to number the frame within the second.
I notice that frame #8 was actually shot before frame #07 because the moving object in the movie is "jumping" back. Is the %q method the correct one to achieve what I'm trying to do?
This is not a new observation, it also happens in motion.