Subtle changes, bugs and feedback

I've found that on some pages, if a comment has more than about 6 newlines in it, it can't be edited. The text gets loaded into the textarea then instantly disappears. Also happens if you paste the same text into an empty "Post a reply" text area. But only specific pages.

Affects:

1. Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/76.0.3809.100 Chrome/76.0.3809.100 Safari/537.36
   
2. Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:69.0) Gecko/20100101 Firefox/69.0
   
   

Doesn't affect:

1. Mozilla/5.0 (Linux; Android 9; Pixel 2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Mobile Safari/537.36
   
   

Edit: Seems to affect pages with images. If I delete all images on the the page, the text comes back into the box