I’m still experiencing the same issue with Spotlight on my Mac Mini M2 with macOS Sequoia 15.0. It only returns search results for applications, not files, settings, or emails.
Setup
Mac Mini M2
Mobile account authenticated against SAMBA-AD-DC (Active Directory-like)
Workaround
I found a temporary workaround that seems to help:
I created a local account (no admin privileges required).
Then, I attempted to SSH to localhost using that local account.
The SSH connection was rejected for reasons I haven’t yet investigated, but interestingly, after this, Spotlight started functioning normally again.
It seems that a local account needs to log in at least once after every reboot for Spotlight to work correctly. This workaround isn’t ideal, but it might help if you are facing the same issue.