Foogallery thumbnail sizes not working

Hi,

Although my galleries were working perfectly, after last updates, the thumbnails of all my galleries are not working anymore. I am using the ‘responsive image gallery’ and the thumbnails are not cropping to the exact dimensions.

The link for one of the galleries that I am facing the problem is the following:
https://www.technautical.gr/our-works/
However this problem is for all Foo Galleries in my website.

Could you help me? Please provide possible solutions.

Thank you.