I've never encountered this bug before.
So a few days ago, my Search Indexer decided to go strange on me. I wasn't able to find files on different drives that are connected to the computer.

I did all 3 options at: Rebuild Search Index in Windows 10 Windows 10 Tutorials

So check this out (refer to the image below for the following):
1) In the top section, if I uncheck the csc folder, nothing happens in the bottom section
2) When I uncheck the red "My Personal Disk Drive", the blue "My Public Disk Drive" disappears from the bottom section. (What?) So when I re-check the red drive again, the blue drive shows up on the bottom again. (Hence: Strange)
3) When I uncheck the blue "My Public Disk Drive", then the blue "My Public Disk Drive" disappears from the bottom section. (Which is correct )
4) When I uncheck the green "The Local Solid State Drive", then the green "The Local Solid State Drive" disappears from the bottom section. (Which is also correct )

So why isn't the Search Indexer working correctly with the red personal disk drive?
Click image for larger version. 

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