Update tag slug to remove the "-2"

I have a Tag on the site called “quotes”. However, the slug that is associated with that tag is “quotes-2”.

I assume there was a duplicate tag at one point, but there is only one tag now.

Is there any way to update the slug to remove the “-2” part of it? I tried to edit the tag and update the slug, but it automatically goes back to show “quotes-2”.

I also tried to completely delete the tag and create a new one, but it still shows up with the “-2”.

Any ideas?