I created a new Gallery with the exact same pictures, i didnt change the settings and added the pictures and sort them correctly like i want them in the frontend, after that i checked it and had the same issue sort like the child gallery with the issue. So i take the same settings(without parent, everything manually) like the parent gallery and still had the sort issue.
I tried the same tactic with the other pictures, they worked. The only different from the galleries are the picture format. in the gallery with the issue we got 3 PNGs and all other are JPEG. In the gallery that works we got only JPEGS.
The Ticket ID is 3118.
Thank you very much for the respond