Note 6/5/20: This issue has been fixed by Xfinity support.
Xfinity Internet customers who are using a PhotoSpring frame and who have the Xfi Advanced Security feature turned on may be experiencing issues downloading photos to their frame. This is due to an automated process within the Xfinity network. We are currently working with Xfinity to investigate and unblock several PhotoSpring server IP addresses.
Fortunately, by disabling the Xfinity Advanced Security Feature, you can get around this issue. Here are instructions on how to do this via the Xfi App. Contact Xfinity if you are having issues turning Xfi Advanced Security off.
https://www.xfinity.com/support/articles/using-xfinity-xfi-advanced-security
We have no ETA on when this will be fixed but this is impacting a large number of PhotoSpring customers at this time so as far as PhotoSpring, this is the highest priority item we have right now.