Filter for closed Milestones don't work

I have a closed Milestone named “December 2022”.
There where some Issues assigned to it, that are not yet solved.

Now I’d like to find all those issues and re-assign them to another milestone… but there isn’t an easy way to do this… (or am I wrong?!?)

So I had the Idea: Go to Milestones, search for the old milestone and find all issues that are still open and assigned to that old milestone.

Good Idea… but gitlab won’t let me do this:


I think it’s a bug, especially as I’m also get same results if I do select “closed” or “all” tab in Issue-List.

What do you think? Is it a bug, or is there a way to archive this?