New group members should see existing shares

⚠️ This issue respects the following points: ⚠️ • This is a bug, not a question or a configuration/webserver/proxy issue. • This issue is not already reported on [Github]( OR [Nextcloud Community Forum]( _(I've searched it)_. • Nextcloud Server is up to date. See [Maintenance and Release Schedule]( for supported versions. • I agree to follow Nextcloud's [Code of Conduct]( Bug description Newly created users (via [OIDC]( using Keycloak) don't see a previously created share. After recreating the share and the users can see the share. Steps to reproduce Users: A, B and C Group: G Share: S 1. A (a keycloak account) created a share S and shared with B (my account, not a keycloak account) 2. B shared with the keycloak group G 3. the newly created account C (a keycloak account), who is member of the group G, doesn't see the share S Expected behavior That newly created accounts see this folder. It works if: • it is directly shared w…