P. 5 (51). This is because the text starts directly on the "part" level, and the header uses the last \chapter title. At first it seems that there is no chapter prior to the next one starting on the next page, but \tableofcontents also is a chapter. Curiously the first page of parts II (93/139), III (225/271) and IV (323/369) don't have a chapter title in the header, even though they feature the beginning of a chapter.
It would be possible to empty out this string by inserting \chaptermark{} at an appropriate place, but I'm not sure where that place would be or if we don't want to handle the pagestyles in a completely different way altogether.
P. 5 (51). This is because the text starts directly on the "part" level, and the header uses the last
\chaptertitle. At first it seems that there is no chapter prior to the next one starting on the next page, but\tableofcontentsalso is a chapter. Curiously the first page of parts II (93/139), III (225/271) and IV (323/369) don't have a chapter title in the header, even though they feature the beginning of a chapter.It would be possible to empty out this string by inserting
\chaptermark{}at an appropriate place, but I'm not sure where that place would be or if we don't want to handle the pagestyles in a completely different way altogether.