I created a new Jira project and started moving tasks there to start with a cleaner enviroment.
After moving the tasks it seemed all ok, everthing was showing up correctly. I then proceeded to delete the empty epics in the first project and seconds later the tasks started disappearing from the second one (all except the one "Done"). If I click on links I had in other documents they simply shot the lock picture saying "You don't have access to this issue".
So ye, now wondering if this is part of the "that's why you never want to delete anything on Jira" or did I do something else wrong? And of course.. any chance to recover those Jiras?