Q: Siri not finding files on my external drives

Hiya:

Just updated to MacOS Sierra, and I am trying to use Siri to find files on my computer and like the title says, Siri's not coughing up files on my external drives (both connected via USB 3 through back of iMac). I've tried turning Siri on/off, Spotlight doesn't have any excluded folders, I tried signing in/out of my iCloud account. I've tried creating a new user account on my Mac (which won't find anything at all). Permissions on my external hard drive seem ok: Read/Write is enabled for Me, Everyone, and admin; "ignore ownership" is turned on.

I'm starting to think this is a design limitation of the software. Anyone else using Siri able to get her to fetch files on your external drives?