Just to let you know - this has been reported to the support desk:
https://jira.atlassian.com/browse/CONFCLOUD-77319
I experienced this behaviour on two completely different sites (yesterday and today):
Add an existing page to a database Title field. In the database interface, edit one of its metadata (eg status).
A draft page will be shown as an identical copy of the original page. Even if you delete the page to the trash, this draft ghost will stay forever (e.g. below: Testpage 3 Draft: Testpage 3 had already been trashed).
Hey Filip - forwarding this to the team to check out. Thanks for sharing.
A workaround is suggested: move the drafts under a parent page and delete that page.