I have solved the problem -- at least in my case. I had a heck of a time importing photos directly connected to my PC. It was the same problem I had in iOS 12 with my iPhone 8. That is when it seemed Apple forced everyone to use the High Efficiency (.heic) photo format.
I got my iPhone 11 in late Sept -- and did not even notice or bother to check that High Efficiency was turned on. I had a bear of a time getting about 500 photos off of the phone in late November, but as I mentioned before I used iMazing to extract them all into a folder. I then changed Settings > Camera >> Formats to Most Compatible (which is JPG).
Today was the first time I did a photo import. I used the standard Windows 10 Photos app. It worked. There were no issues. I spoke to an Apple rep on this also. For those of you who want to import in High Efficiency (.heic) and not change Formats under the Camera settings, she suggested going to Settings > Photos and under Transfer to Mac or PC -- changing that from Automatic to Keep Originals. .HEIC is now supported in Windows, but I just feel more comfortable with JPG.
Since iOS 12 -- something was screwing up in Windows as the iPhone attempted to change those imported photos from HEIC to JPG. I would rather just leave it on JPG for now. I don't care about saving 40% storage space.