Brand New iMac Pro running the very latest MacOS Catalina 10.15.1. Running Virtualbox 6.0.14 (latest). Using Whonix-XFCE-220.127.116.11.3 image.
In any other display resolution except the default micro sized one loaded at import the workstation and gateway GUI become unusable. Choppy, slow - mouse clicks can take 15-30 seconds to register (if they do).
I followed the instructions "5. VirtualBox Screen Resolution Bug " on this webpage (/wiki/MacOS) but this does not fix the problem.
I’ve tried. “VBOXSVGA” seems to be a slightly more usable than any of the others. Unfortunately, when I am running the whonix images my system crashes nearly every time (hard) when I am playing with the graphics or display resolution so it’s hard to really test. This is a brand new vanilla setup and latest software and new hardware. This does not happen with Ubuntu or Windows.
Maybe a warning for prospective MacOS users until this problem get’s sorted out.
Happened to be browsing the forums to see if anyone was having similar experiences. Same setup as OP (except MacBook Pro). Problems seem to be occurring only on the Whonix image. The system halts and reboots if you tinker with graphics too much. Also resolution changes are weird. You can set 1650x1050 but it is still very small window size on the screen. Increasing resolution just makes it more difficult to interact with whonix and behavior is not as expected as with other VMs. Currently, only real workable solution I habe found is to run whonix inside a nested linux VM. However, AnBox does not work well like this.
I don’t have a vanilla Debian but Ubuntu 16.04, Xubunutu 19.04 both work fine in virtualbox. So Does tails, windows and a lot of other VMs I have. Problem from my experience so far (and I believe the original op) is whonix only.