This is my first installation of KDE Neon on a Lenovo ThinkPad A475, with an AMD processor and graphics.

I’m very impressed with KDE Neon, but I can’t keep it if I can’t get it to go to sleep. Nor will it power off at shutdown. It instead will run up the fan for a few moments, then settle into a non-sleep state with the fan running and a black screen.

Is there a different graphics or AMD power management driver I need to install to get this laptop to sleep or power off?

Neon 5.23.4
Kernel 5.11.0-43-generic(64-bit)
AMD A10-9700B
Radeon R7 graphics
Renderer: AMD CARRIZO (DRM 3.40.0, 5.11.0-43