This question already has an answer here:
Currently, when viewing an edit where MathJax is edited, the rendered output side-by-side diff breaks the MathJax rendering. This is particularly annoying when reviewing edits, as the actual result after editing is unavailable.
Of course, it would be best to change the diff view to not break edited MathJax, but a perhaps easier improvement would be to simply show the rendered output without the diff, as then the MathJax will be rendered correctly (if the edit placed the MathJax delimiters correctly. In fact, this is one of the hardest things to check right now!)
This is a pretty old issue and my suggestions are nothing new:
But this might be a simple improvement that would make (community) moderating easier.