It’s something I’ve been observing for quite some time, but I can’t reproduce the cause:
Most of the times I can set a custom duration and save it as default, in my case 00:00:00:30, without any issues
Sometimes that isn’t possible:
** Default will be a different duration
** Duration can be set from 00:00:00:02 - 00:00:00:24, but if I increase it once from 00:00:00:24 it jumps to 00:00:01:00
** Any value in that range of 00:00:00:24 - 00:00:01:00 can’t be used or saved
The last 2 digits are a frame count, not a time. You are running at 25fps, so the frame count goes from 00 to 24, then it resets to 00 and increments the seconds by 1.