Hello , i was having this exact issue, and i have seemed to figure a way around it.
So, your iPhone or other device would want to connect automatically to the one drive on the Microsoft account. But what you will want to do is click cancel before it finds all of the files and exit the one drive tab at the bottom of the screen and open your files of your computer.
The one drive had a max storage of 5 GB ( at least on my account ) which was not enough for all of my pictures.
So using your files on your computer is probably a better bet . I just dragged the photo files from my iPhone to the pictures on the computer.