black screen after restart

Black screen after reboot -- the mouse cursor is visible and responsive but the whole screen is black. Hitting random keys doesn’t seem to do anything, only second, hard reboot solves it.

I would not worry if that had happened once or twice but it seems to be a pattern.

It happens both with ’normal’ mode and clam-shell mode with Thunderbolt Display attached.

MB Pro 16’’ (2021), M1 Max, 64GB, 4TB storage, macOS Monterey