"This device is unreachable"

It used to take me just minutes to transfer pics from my iPhone 7 to my pc. I've been at this for 2 days now. It would work for a couple days then back to the error message. I searched online and found a remedy that has worked for some. I changed the Photo Setting from Automatic to Keep Originals. Downloaded a HEIC to JPG converter and downloaded a total 4 pictures before it started all over again. Now it's back to square one. This is pure ****.