Spotlight Not working-Tried Everything

When I run spotlight on my iMac system drive I get "No Results". External Drives work fine. I've been trying to fix this for months.

Thanks for any advice or direction.

Things I've tried.

Tried to add iMac drive to Spotlight Privacy, but encounter “Can’t be added or removed because of an Unknown Error”

Restarted SystemUIServer in activity monitor.

Used Terminal to run sudo mdutil -E /and got “Error: unknown indexing state.”

Booted too Safe mode.

Ran Disk Utility in safe mode. At first it said there where too many errors to list, then ended by saying it was OK and restored it to boot state.

Reset the NVRAM.

None of these worked.

Spotlight DOES work when I create a fake user account.

Apple says i need to install the latest software. (of course they do!) Not an option for me.

Some details that may or may not help:

iMac 2019, MacOS 10.14.4

I was running an iMac on High Sierra that died. I got this iMac and restored the TimeMachine backup from the old machine while it was in the shop.

The old mac was called iMac01 so I changed the new one to iMac02 after the TimeMachine restore to avoid confusion.

iMac Drive is formatted APFS. .6G of a 2TB drive used.

There is a disk image that mounts every time I boot. It says “Update”. I can dismount it no problem. Not sure what that is. It was there when I bought it.

When the system boots there’s a popup that says something like “Some features are not compatible with this disk” but gives no indication of what that is, or which disk it is.

I'm using a 3rd party app and it works (It works like the original "find" function on Macs. That's a good thing.) But having a working Finder window is convenient.