I’ve been having the same problems but only recently, so not sure if something has changed? I’ve tried the MakerCAM workaround and yes it does work, but I’m using greyscale fill to tell Easel how deep to carve and that doesn’t make the transition…
So I still have a problem. 
(I have 130 areas in this SVG, all with different depths!)
EDIT: Also same problems in Chrome and Firefox. Any help much appreciated as I’m actually stuck on a particular project because of this!