Why can't new group members see folders previously shared with that group

I’m using nextcloud 18 (within nextcloud’s docker image) and I noticed that when I add new users to a group they won’t see files that have been shared with the group members before the new users were added to the group.

I also have much older nextcloud 15 instance (not dockerized) where this behavior is not the case. Files shared with the group are visible both to new and old users.

It seems like a bug, but maybe there are some more parameters that I should take in consideration when sharing folders with group.

If it helps - I disabled some of the plugins:

  • Auditing / Logging
  • Calendar
  • Collaborative tags
  • Comments
  • Community Document Server
  • Default encryption module
  • External storage support
  • Federation
  • First run wizard
  • LDAP user and group backend
  • Mail
  • Nextcloud announcements
  • Notifications
  • Photos
  • Recommendations
  • Support
  • Talk
  • Text
  • Update notification
  • Usage survey
  • Video player

What is especially peculiar to me is that within Activities tab, activities related to the “invisible” files are shown.

Now that I re-enabled Notifications I noticed that new users recived notifications to accept file share. This is weird because in Settings>Sharing>Accept user and group shares by default is ticked.