Laptop does not come on with an external screen?

I connected my laptop to my monitor via Hdmi. Since this morning I have to pull the Hdmi cable out of the laptop, then let it boot up and then I can reconnect the monitor. But if the laptop is connected to the monitor, it boots the image remains black

Have you ever tried Windows Symbol + P.

I just tried it and it doesn't seem to work

What is entered in the BIOS as the default monitor? Are the graphics BIOS and drivers up to date?

The BIOS says that the laptop screen is used as the first monitor

Too bad. That would have been an easy solution. Is there an "auto" setting? Would be illogical, but if it helps…