Hi Greg! I think I finally have everything fixed. My catalogs are both back (and backed up) so I switched back to my original issue, which was that I couldn't get my HEIC photos to import to PSE2020. That seems to be resolved now too.
I had already installed the extensions for HEIF and HEVC and set my iPhone13 to Download and Keep Originals, as well as changing the other setting to "most compatible" for future photos. Rather than trying to import again, I found an article that said to connect the phone to the computer and look in the internal storage folders. Every file in there was listed as a JPG, even a few that I verified are HEIF on my phone. So I dragged them all to an "iphone13" folder and then imported them into PSE2020 without any problems, at least that I can see.
I am, however, having one problem. I realize I haven't really used the program in a long time, but you'd think I could figure this out. I was trying to transfer photos from the "iphone13" folder in PSE to the appropriate year folders that already exist. I realized I didn't have a Year 2019 folder or a Year 2020 folder, so I created them, but they disappeared. They exist on the computer, but I can't find them in the catalog, and I can't recreate them because it says they are already there. I tried closing and reopening PSE but they still don't show, even though they are in the correct place on my computer. Is there a way to search for a folder in PSE?