I haven't encountered this yet, maybe because of my damn multi-layered images (the image itself is 1024x2048, and then scaled down by 0.6 (the iPhone renders the same way) the loona consists of 6 such images), which Renpai doesn't like to work with. If I have a lot of free time, I make the images the right size so as not to scale them down.
grammar is my weak point, but in most cases I used deepsik to rearrange the sentences into English