Originally Posted by adv_dp_fan
Played around with it a little more and can repeat it on different ebooks. Basically I'm changing the "type" setting on the cover or deleting it completely from the <guide> section. If I make the changes outside of Sigil, when I load the book into Sigil it correctly shows my changes but the moment I hit save it appears to re-write them to its own form.
Other changes I make to content.opf don't seem to have an issue, just any relating to the cover in the <guide> section.
Can you open a bug report
with this explanation please.