I read up to about page 9.
Have you people tried importing via the file explorer method?
- Open up file explorer with your iPhone plugged in (USB connection).
- You will see the name of your iPhone listed in the left.
- Right click the name (iPhone) and select 'import pictures and videos'.
- Then follow the instructions.
This method worked for me, instead of the Photo App method.
I was clearing out my old iPhone 7 Plus.