It looks like I cannot add anyone in a private group :
When I invite him I receive "Player has already been invited to this group"
and when he tries to join the group, he receives : "You already have a pending group request"
But… nothing appears in the admin pannel of the group.
So I put it in a public mode but I really would prefer this group to be private. Thx.
Otherwise, we cannot also delete the group, I think it should be added
(ps : it is actually pretty urgent because it is for an european tournament I organize with a Swiss confrere. )