Editor X is super slow on Safari

Editor X runs smooth on Chrome but on Safari, it’s way too slow. It’s almost not usable, taking a lot more time to respond to even simple functions. Does anybody else face issues with Safari?

One of the few bugs I noticed was while trying to edit text in text boxes, the size of the text increase 2x or so when the text is selected. The size reverts to the original once the editing is completed (meaning, no effect on output but it is confusing and not the intended function of the text editor). Am I missing something? Perhaps a plugin or something of that sort?