I have a large external drive, that contains several hundred thousand photos connected to my Mac Studio, running MacOS 12.6 I’ve just noticed that Spotlight isn’t indexing it. When I look in System Preferences → Spotlight → Privacy, the drive in question is not listed, so there’s no reason that it shouldn’t be indexing.
How can I enable Spotlight searching for this drive? (I’ve searched the internet, and not come up with a solution.)