Clamshell mode doesn't work - MacOS Ventura

Hi Everyone,

I was wondering if anyone has experienced the same issue with "clamshell" mode, and knows the solution.

I usually use my laptop with only 1 external monitor, and the built-in display is turned off as I keep the lid shut. This had been the case until I upgraded to Ventura. A couple of annoying things I would like to address:

1) The built-in display is always activated even when the lid is shut - and in "Settings" I only have three options: a ) main display, b) extended display, c) mirror for the external display. Is there away to turn it off completely?

2) Besides, if I use the MacBook alone (no other devices connected to it), it won't go to sleep mode either, when the lid is closed. I can actually see screen is on by looking through the tiny gap from either side.

Please let me know if you have the solution.

Thanks in advance.

DW