Zacks comment that right clicking the iPhone in Windows Explorer and importing from there works for me. It imports all photos rather than just new but at least it works.
Separately, I did a Repair on Microsoft Photos as suggested elsewhere in this thread, and that worked too. It no longer hangs up and I can import only those photos that I select.
Win10 (all latest updates installed) and iPhone 7+ running IOS 13.3 here.