I don't exactly know what's going on other than it's like lazy loaded images are reloading and sometimes loading, unloading and reloading over and over. Sometimes it's just like an image reloads making it look like it's flashing. But on my PC and phone (both with Firefox and Firemonkey and Tampermonkey respectively) it makes Kbin almost unusable because as I scroll down, images will pop out of existence which jumps the posts upwards, losing where I am. To get around it, when I want to tap on an upvote or go to the comments, I have to scroll really carefully so as to not let the image above from unloading.
I was using KUP v3.6 but even updating to the latest, it still has the same problem. :/