On every other version of Ununtu I have installed, I plug in my USB hard drive when I want to look at the files on that drive. I plug it in, hit the "open other locations" button in the "file" section and they are listed. But 20.04 doesn't seem to act this way. I have no idea where it is. When I plug it in the drive light flickers for a few seconds and then stops, just like usual, but nothing shows up on the files section.
Oh, F*, do I feel like an idiot! I had put a brand new HDD into that USB connection and had forgotten to take it out and put the old one in, so OF COURSE it didn't show up. Once I put the old drive (that I had wanted to look at) into the USB connection, it showed up very quickly. Oops! As usual, no problem is bigger than stupidity. :-)