HTML Editor 'closing'

Hey! For some reason every time I try to scroll down on the HTML editor the text box ‘scrolls inwards’/contracts as I bring my cursor towards it and I can no longer use it.

I did see this question asked before and the solution was to check if the browser was on ‘90% zoom’, however mine is not so I’m not sure what to do!

I don’t really know what you mean, can you provide a screenshot or video?