Finder thumbnail images not showing when filtering using tags

Hello! I am on Mojave 10.14.6. I am trying to use tags to filter my many many images on my external hard drive. Outside of my tags not seeing things I have tagged, I am getting this issue. My thumbnail previews look like this when I click on the tag. I have tried just about everything. Deleting the plst. file, relaunching finder. Everything.

What is even worse, Is that the image preview shows up jsut fine, when something on the main drive gets tagged and the I search with the filter like so:

I would seriously love some help.