Syncing between "friends" not working - need permissions when permissions granted

I recently added a friend who also has a Plex Pass membership. I have given them access to a few libraries and have explicitly granted them permissions to sync content (on the web interface, Users -> Friends -> Restrictions…).

They can see all my content, they can play it just fine, but when they try to sync for offline viewing, it says something along the lines “the owner of the server needs to grant sync permissions”, which I have.

Their device is an iOS device if that matters.

What are we doing wrong? Or are we not doing anything wrong, and this is some sort of a platform bug?

I apologize if this is duplicate post or a known issue; I’ve scoured these forums and I can’t find anything that talks about this.

Thank you!