After Compile German umlauts in style names have lost their little dots—Ü becomes U, Ä A, and Ö O. Also ß is converted into an s.
What’s really nasty about this is that the German word for heading happens to contain an Umlaut—Überschrift. So if one sets up a Compile format to just create a generic but structured document there won’t be any structure because these umlaut-less heading styles are not defined in the target word processor’s standard template and therefore don’t have any level.
Interestingly, all this applies to Pages while LibreOffice has Überschrift of all levels with an umlaut—but only Überschrift. All other style names do lose their Umlauts too. I suppose LibreOffice does some thoughtful parsing when opening a document.
No Word here, so I can’t tell how it does handle this.
The simple workaround is to use the English term heading because the word processors translate it into the language of their respective user interface. But as this goes only for headings and users normally don’t know anything about this bug it needs fixing.