Laptops are weird. I have one that lost its screen in use with a monitor. The same monitor I use with the work laptop (HDMI connection). I also have a second monitor connected through an adapter into a usb c port on the wotk laptop
Realised at the weekend my screen less laptop has a usb c port. Plugged in the second monitor whilst the laptop was switched on and the screen lit up with a desktop. Just had to flip the screen settings to get the mouse to move correctly between them.
Switched off. When I switched it back on the second monitor was blank.