Corrupted images with Flex objects plugin

I am on Gvar with Flex Objects 1.3.5 (ngixn + php-fpm 8.1).

I recently discovered that I can’t attach any image to any page through Admin GUI.

As soon as I attache the image and save the page I will be presented with a squire (placeholder) with image extension on it. Clicking on image info shows ‘Can’t read image data’.

And yes, if I check the page directory there will be a file named as my image but with 0 byte size.

I can disable flex objects and all will works as expected.

Can one help me to debug and fix the issue pls ))