Microsoft announced three changes to Entra ID cross-tenant access settings that will improve how the settings work for large enterprise tenants in particular. One of the changes improves the blocking of Entra ID B2B Collaboration invitations extended to allow guest users access resources in a tenant. When Entra ID evaluates whether it should issue an invitation, it now takes the blocklist (if set) in the B2B collaboration policy and cross-tenant access settings into account. It’s the way things should have worked from the start.
https://office365itpros.com/2023/09/13/cross-tenant-access-settings/
