Synchronizing with iOS phone to cloud one-way issue

I struggle to update changes made in contacts on the iphone (ios 15.3.1) to NC 23.03.

Changes made on NC.23.03 are reflected on the iphone, so this works well.

Calendar syncing works both ways, so it is only the contact sync that for some odd reason is not working from phone to cloud.

Looking at the NC log there is nothing special indicating any issues. I have also waited for a long time to see if there is some time-lag on the iphone to sync to NC due to the fetch mechanism, but to no avial.

Any ideas?

Many thanks in advance for any input.

UPDATE: I figured this out. It turned out to be a Groups issue. When importing from Google, or other sources, group names follows the import. When adding a new contact on the iphone this contact is automatically added to the “Not grouped” group. Will keep this post in case it helps others.