Until recently I was quite pleased with the responsiveness of the MSE editor field: preview (and thus typing) seemed to be proportional to the number of formulae input, but something happened and now even short answers take a lot of CPU (I can hear the fan turning quite noisily), and the entire experience is quite annoying: the letters that I type get collected in a queue from which I see them being output o-...-n-...-e-...-b-...-y-...-o-...-n-...-e. Have the MathJax gods changed anything in the code, recently? Is it possible to disable the preview (but having the possibility to re-enable it at will during writing in order to check the rendering from time to time)?
The machine I am using is the same, and the browser is always the latest version of Firefox with just uBlock (as extension), and Flash, Java, VLC and OpenH264 (as plug-ins), so it can't be from me.
(I am aware that similar questions have been asked, but they cannot be considered duplicates since they may always point to new bugs in the SE software).
A clarification: when I say "a MathJax bug", I believe that in fact I should say "a bug in the MathJax renderer". The one that causes my problem is HTML-CSS. I am going to switch to Common-HTML and see if the problem persists. I must also add that this behaviour is random - sometimes preview is perfectly usable.