Default sharing image not working

Hey. For some reason the default sharing image is not working. The plugin works great on pages which have some image to share, but if my page doesn’t have an image, it shows my site title image (header logo) which can be changed from the theme settings. This happens at least with Facebook. Could this be some kind of compatibility issue with the theme or could something else cause it? I’m using Quark theme and I have made child theme from it.