The "Frame Level" slider in the position section of group configuration no longer properly positions the level of a group.  E.g. a group with a frame level less than another overlapping group will still draw over the top of that group if it appears later in the group order.

Posted by CurseForge user canofbutter | Imported from CurseForge issue #1631 | Raw

Looks like Blizzard broke the behavior of :SetToplevel() and made it not get reset anymore.

Basically, when you click on a group (to configure one of its icons, for example), that group is brought to the top. This lets the group that you're configuring be displayed on top in case you have overlapping icons. It used to be the case that this brought-to-top state would be reset, but it appears to be no longer true, so I'll have to remove that behavior so the setting works correctly now.

Posted by CurseForge user Cybeloras