SOLUTION!
Hey everyone. I have this problem since September. I tried everything and every time my Photos App freezes while it scans for import from my iPhone.
First of all I tried the process to a new PC with the exact same windows (and photos) version only to find out it works normally and it is not an iOS issue.
What I did is this:
Press import as normal while you remember the number that your scan freezes and press "Cancel" once, before it reaches this number. Basically, dont let it freeze and press cancel in time. If it freezes, kill the task and launch again. Just a random number
before the one it freezes works. After that, press import again and you will notice that the scan number continues from the one you pressed "cancel". But this time it will reach the max number and you will get to the "choose what to import" screen.
I tried the process 10 times exactly and it worked all times. This looks like a good workaround until the App gets fixed (maybe in November update?). Please try this and post.
You are an absolute star. Thank you. I have still to move all of my photos but I have made a great start. Thank you so much.