Why does QuickTime shorten my image sequence videos?

I did a time lapse of roughly 3500 images.

if I directly go from SD card to QuickTime image sequence it makes a full length video of 2:06 at 30fps.

I edit those same 3500 images in Lightroom classic and then export them to a folder, if I create an image sequence with those edited photos the video is only 1:29 seconds, why is QuickTime shortening the video?

QuickTime will do the same thing with 5000+ Photos…

[Re-Titled by Moderator]