@sickrandir Yes indeed, that was #861 goal to fix that. Apparently there is a bug with Safari but I do not have a Mac to test/fix that. So maybe you could look into fixing that? If you can't, your best bet is to open an issue and hope someone will take it up.
the problem seems to be with the sketch canvas. I would first try to display the sketch canvas on the screen to check whether everything is normal in there. If it looks normal, that means that there is an issue when drawing the sketch canvas into the main canvas.
to display the sketch canvas, you just need to attach it to the DOM in drawer.js