[UffelenE]

Product: Kobo Glo
Firmware: 2.8.1
Plugins: -
File types: EPUB
Sideloaded or from Kobobooks: Sideloaded
Steps to reproduce:

1. Create a bookmark in an epub book
2. Go back to home, and tap on the bookmark-row on the book.
3. Bookmarks show correctly. Select the bookmark.
4. In the right bottom menu, select go to show on page
5. So far so good.
6. Go back to home screen and go the the bookmarks of that book again.
7. The bookmark now shows 0%.

Current result: Bookmark shows 0%. But it still works.
Workaround: No