Thank you dcoke22 for answering at all.
I have MakeMKV on more than one machine. The Version 1.17.4 is acting the same an ALL machines.
Rolling back to the 1.17.3 Version fixes this problem on ALL machines.
On one of the machines I had installed MakeMKV Version 1.17.4 before ANY OTHER version if it was installed on that machine and it had the exact same problem. deinstalling that version and installing the 1.17.3 version (because a rollback can't be done when it was never there in the first place) the problem was gone and it was working like it should with all languages.
So from my side it IS the version 1.17.4 that has the problem and ONLY with that version NO MATTER how it or the other version was installed, in the end the version 1.17.4 ONLY knows english and the 1.17.3 can do all.
Who else has an idea what can cause this?