I am not sure it’s my computer’s problem or a bug. At least, I didn’t have this problem in 12.1. In sleep mode (suspend mode), when you try to log back in, I got the blank screen.
Install the latest NVIDIA driver if that is your GPU manufacturer.
This is not my case. I am using ati card with drm-radeon.
You need to explain your setup in detail or no one will bother trying to help.