Originally Posted by NiLuJe
So, yeah, if what's in there isn't bogus (and it doesn't look like it), and the K3 chokes on this (or only honors the first entry: you start on the TOC instead of the 'proper' start), probably a K3 bug. (Calibre only puts a single entry in there: the start).
I really appreciate you investigating this. Another mystery solved. To be honest, I hardly ever use Go to Beginning anyway, but this information might be useful to KDP publishers, if they get complaints from K3 FW3.4 users about this issue.
But then again, most K3 users probably won't notice this problem.