To reproduce this, I need to post twice, since the max images on any given post is 3.
Here is how I found this alignment problem. I was making a dynamic LS sig for a fellow guild member when I noticed, when centering 2x images, there is a wide space between the two.
For demonstration purposes, I've used exaggerated colors.
First example: Default left alignment, as you can see, the images fit snugly as preferred.


Next post to show the centering gap.