Images don’t show up.

I have a clone of the Website running on metzgerhof.at where the plugin works fine. The same config doesn’t show all images properly on metzgeralm.at.

What could cause this error?

Comparison of one image link for both sites:

One metzgerhof.a the image is loaded:
(https://scontent.xx.fbcdn.net/v/t1.0-9/s720x720/42143641_2347782578571775_6390751636679032832_o.jpg?_nc_cat=104&_nc_ht=scontent.xx&oh=1e8444be0da942fbb5a46e2c0e3cc58e&oe=5D31B7E4)

On metzgeralm.at i get an “URL signature expired” error:
(https://scontent.xx.fbcdn.net/v/t1.0-9/s720x720/42143641_2347782578571775_6390751636679032832_o.jpg?_nc_cat=104&_nc_ht=scontent.xx&oh=0d2982d8106c92618387fc58e67cd475&oe=5D0A2AE4)

Thanks for Support,
KR
Gerald

The page I need help with: [log in to see the link]