I can't give you a reason for why the hot corner doesn't work in your VM, but I can tell you that the hot corner works just fine in Gnome 3.36.1 on my Solus laptop.
I don't see an option in my Gnome Tweaks tool to enable/disable the Overview, it might've been removed in an update because Gnome 3.36 changed a lot of things on the backend, so for better or worse, it is what it is now.
However, you can still tweak the custom hot corner with a few different extensions. Two that I know are of these two:
https://extensions.gnome.org/extension/1362/custom-hot-corners/
https://extensions.gnome.org/extension/358/activities-configurator/
Maybe give those a test out and see how they go in your VM, but it should run fine if you were to install Solus. Hope this was helpful!