Does anyone how how I can diagnose and fix this problem:

Sometimes, but not always, when shutting down the process does not actually complete and the computer does not turn off.

The screen turns off but the keyboard backlight is still responsive, the fan is still going and the power-on LED is lit. Because the screen is turned off I can't interact graphically with the computer and have to just hold down the power button and do a hard reboot.

I haven't tested it properly but I get the feeling it happens more often if I have been doing audio work.

Debian 13 GNOME 48 Intel Core Ultra 7 Laptop