The virtual device display is black.
The device display is rendered using WebRTC. If the device display is black, then something is probably blocking WebRTC connections.
1. Add-ons and extensions
If you are using add-ons and extensions, make sure that none of them block WebRTC communications.
If add-ons and extensions block WebRTC communications, disable them when using Genymotion SaaS.
2. Google Chrome/Chromium
There are known issues with Google Chrome/Chromium v89 and below with WebRTC communications.
If you are using Google Chrome, make sure to use Google Chrome/Chromium version 92 or above.