I searched the forum and found some similar but old topics and not really an answer why this is happening.
I have many galleries, and upload many images to a single post. In the backend images are not sorted by filename. It seems random, maybe date. My galleries show pictures in the same order.
I always use the same naming scheme as to avoid order problems
2019-06-15-Image1
2019-06-15-Image2
2019-06-15-Image3
2019-06-14-Image1
2019-06-14-Image2
2018-07-12-Images…
Etc
Other naming schemes don’t work as expected either. Any ideas?
regards