Hello.

To help me to better understanding the issue, please answer on the follow questions.

* If you go to the menu "Bookmarks" > "Show All Bookmarks" can you see the encrypted bookmarks ther?
* Do you have any other addons that working with bookmarks, etc, like hide/show bookmarks, shareing bookmarks with other devices.
* If you can see the bookmarks in the normal views (not in the addon) can you click on it, does it working to open the link and can you see a dialog for enter the password?
* If you can see the bookmakrs but not working click on it, copy the link and try to decrypt it at https://linkpassword.evigfilosofi.se/

Finaly for answer you question about change password, you can't but you can decrypt them and then encrypt them with a new password.