Dropped some issues in the backlog on the GitLab repo. Looks like you can't reorder issues within a board (label), just swap labels.
On the one hand, that's annoying, as it means prioritizing stuff is harder.
On the other hand, it's a good spur: Stop mooning over your backlog, pick a task, get it done, and then worry about what you should do from that new, more informed, improved position.
I'ma embrace this limitation and make it an advantage. :)