Unable to transfer photos from iPhone IOS 14.7.1 to Windows 11 using File Explorer or Windows Photos app.

I usually import photos from my iPhone to my Windows 11 PC using the Windows Photos app. However, after choosing "Items since last import" it manages to import some photos and then stops with a "Try Again" window pop up. I tried using File Explorer to copy the photos not imported and the file type is .JPG but with a size of 0KB whereas the size on iPhone is 274KB. I read a different post to this community which suggested I do the following:

1. On iPhone go to Settings>Photos
2. Scroll down to the bottom where you can see "transfer to mac or pc"
3. My setting was "Automatic" and the poster suggested changing to "Keep Originals" and so I did!
4. Then remove the iPhone from USB and re plugin - did this a few times until the iPhone DCIM turned up in Windows Explorer again.

This is what I found:

• Now I can see that at least one of the photos that failed to import to Photos now has .HEIC as the file type and a size of 91KB. I double clicked on the photo and was asked by Windows which app I wanted to use and so I chose Photos.
• Eh voila! The photo with file type .HEIC opened.
• I then checked to see of any of the photos that had successfully imported previously now had a filetype of .HEIC.
• And...this is the weird part...some had!
• So I opened the .HEIC version of the photo from File Explorer with Photos and also opened the .JPG version of the photo inside Photos and...there is no discernable visual difference except the .JPG version is 1.38MB and the .HEIC is 475KB.
• I then opened Windows Photos and did an Import choosing "Items since last import" and suddenly I had 962 photos import that I didn't know had been missed before!

My 1st question is - why was Photos able to import some of the iPhone photos as a .JPG (which were .HEIC in the iPhone original format )and not others until I changed the iPhone Photos setting from Automatic to Keep Originals?

My 2nd question is - whilst I cannot see any difference between the .JPG photo and the same photo but with .HEIC format - as they as different sizes I am thinking that the .HEIC version is somehow inferior from a quality perspective - is that true?

My 3rd question is - who needs to fix this issue as I would prefer that the iPhone Photos setting was Automatic so that the Windows Photos app imports as a .JPG not as .HEIC?