Hello Angus, it could have been your Facebook Token has expired.
Can you please do following:
- sign out from Pixoto
- on Facebbok apps page find Pixoto and remove it from apps
- sign back into Pixoto account
and your Facebook should be automatically connected.
This however will not post awards you have already won.
Top post them (after you reset Facebook token), please go to either awards page or image detail page for which you want to share award, and hovering over award you can select Share on Facebook. You will need to do it for each award you would like to share. Or you can check your e-mail notification(s) about awards and there you can see link for sharing on Facebook.