Rights applied for a group are not updated after rename of the group page on sub wikis

On a sub wiki

• Add a right in a page A for a group B
• Rename the group B to C
• Go back in page's A "Page Administration" and see that group is updated and the the right is not preserved
• Rename back the group C to Group B
• Go back in page's A "Page Administration" and see that group is updated and the the right that was previously missing is visible again.

Meaning that the rights are not gone but not properly updated after rename of the group page .
You can check the Object mode of the page or Page Administration ( depending if the page was on Page or Page and Children) and you'll see that an Object type of Right with the previous name of the group is there. It wasn't updated with the new group name after rename.