As I said in my last reply to get the best solution you have to contact the theme Author.
I have checked your catalog please check theme option is there any settings to set all catalog image will show same size as like thumbnail size. If not you can try to upload all images with same resolution mean same size images. You have uploaded different sizes images for catalog that’s why design has broken. You have to upload same size images.
Again The best way to get this answer is Contact your purchased theme Author.