Duplicated pages -> cannot delete.

Twice, I have tried to upload a chapter to Global Comics.
Both times, a random page has been duplicated, so there are two pages EVEN AFTER I delete the page that was duplicated. It appears fine in the issue editor, but the moment I preview, both pages are permanently there, messing up my margins and page turns (in addition to the duplicate page-I could've tried to ignore it, but it fricks the whole chapter). 
Relevant info:
-46 pages were uploaded as a zip
- I added a cover and dragged it to the top a few pages at a time because you can't scroll while dragging a page.
- I should be sleeping rn.

Additionally, please add in the page grouping settings a 'set alone first page' option- most manga chapters are made this way, and if you have an even number of pages, both of the current options do the same thing.