i get the Mac well synchronized with cardDAV and Nextcloud. However, when I create a group of addresses on the Mac it seems to be a single address in the Nextcloud (not a group)?
When I create a group in the Nextcloud, it does not appear on the Mac.
Nextcloud currently only supports the vCard 3.0 format! See also this discussion:
Be careful about wording, that is not true.
We support both 3 and 4 formats. vCards4 can also have groups in the categories field of each contact record.
The only thing we do NOT support is groups as individual vCards, vCards versions are irrelevant here.