I always forget this. I remembered for this correctly because one of my test site the group names changed right, but the unicode_usernames setting was enabled for testing purpose. I forgot this step here.
But I didn’t enable this setting for now because I don’t want to enable it for usernames. So now I use names without accents in group names. We’ll see how it goes.
Thank you so much for your help!
Edit: Just updated now and everything works as expected! Thanks again!