In my test (on my testhost), everything with the photo upload via mobile works as expected.

On your website, it also works, but only with small photos (screenshots or logos).

Please retest with a small photo or adjust the maximum filesize for photos here:

In my test on your site, it did not work with normal/bigger photos, but it worked well with a smaller jpg.

Please also make sure to allow more image-file types, as for example jpeg or webp etc.

I close this one, as we found the issue 😊