It being Christmas an'all, I'm having trouble with Contacts.
I can make a new Group, but not move it up and down the 'Index' list on the LHS.
I can't add any contacts to it, either.
I haven't contacted Apple help yet but they may be able to help. Contacts all went a bit funny at an update a while ago, when it managed to duplicate all the groups, which was annoying but only inconvenient. Apple in Solihull just shrugged a bit and said 'Try Phoning Help', which I didn't do.
Any solutions out there? macOS 11.7.10, mid 2015 machine, Contacts v13.