M1 mini screen will not display after sleep -

This is a relatively new problem - everything was working great for as long as I've had the mini, but something has changed. Now, when it goes to sleep, I cannot get the display to respond. I can shake the mouse, and see the mouse pointer, and the screen is getting some illumination (back light is visible), but it stays black -

I've tried unplugging/plugging power to the display, also HDMI cable, with no effect. I've disconnected peripherals (a pain to remember to plug them all in every time) but that hasn't had any effect either. The only way I can get the screen back to is force shut-down the mini with the power button, then start it back up. I know the mini is running fine, as the security camera system on it is responding and sending me emails when motion is detected, but when I walk into the warehouse to use it for anything else, I cannot wake it up -

This seems to have started with a Ventura update, but I cannot swear to it - I've been trying everything I can imagine when I have had time, changing all the display/energy/network settings that might have had a part, but nothing has helped and I have no idea what else to try -

Mini M1, 16gb, Ventura 13.2.1 -