Newly created Variables in a group are shown in a duplicate group of the same name

I’ve spent a long time translating a colours in my design system into variable. Now for some reason I can no longer create a variable in a group for example

Moss / 300

If I trying to create a new variable in this group it will create a duplicate of that group. There is no way of creating a variable in any previously created group without it creating a duplicate.

Has anyone else noticed this bug and found a solution?