IPhones will not allow an image to be uploaded into a Preview template. These is a big issue given the prevalence of iPhones in the world.
I could not find any topics addressing this issue.

I have a problem downloading images from an iPhone but no issues with uploading. Just opened a discussion about this: https://support.fancyproductdesigner.com/support/discussions/topics/13000030238

Problem seen for both Safari and Chrome on IOS.

FYI.