LaTex Export included Files not found

I have a xwiki site with several pictures in it. I had to include these from a different xwiki site, by using the included tag. They are not attached by the exported site itself.
I used the LaTeX exporter and the suggested docker image to generate a pdf file.
While generating the pdf file I got an error, that these pictures are missing and the pdf conversion fails.
The path of the missing files includes letters like ä.ü.ö. These are not proper converted in the LaTex output (Anhänge = AnhC3A4nge).
Do I have to reshape my xwiki site in order to get a pdf file via the LaTex exporter? Or just simply some encoding is failing?
Using the xwiki pdf exporter is not an option.

Xwiki Version 11.10.2
LaTeX Exporter 1.9.4