The only thing that works so I can actually use my laptop is my HDMI port to my external monitor. Otherwise my builtin monitor is completely black. I switched to “Testing Updates” to see if this would get fixed sooner. My specs are in the picture.
Also for some context, I had to switch my external monitors refresh rate down to 120hz. At 240hz it would flicker in an out for a few seconds at time. I used to just connect my laptop to my monitor via usb c. That no longer works. Only my HDMI port does. Before updating to 44 everything worked out the door with zero issues.
First of all, I would suggest you switch to DP (display port) as it has higher rate than older hdmi. Or get an hdmi 2.1 combo (cable and monitor have to be both 2.1 compatible) if your port allows it. You will also need to set the GPU settings, like I did for the discreet gpu, else it will mostly use integrated graphics. For the main monitor, I suggest making different sets for either monitor (maybe even lower the laptop monitor settings if you have to).
You could be using resolution conversion to apply same settings for both screens, and that might bug it out.
Also, as it is a laptop, maybe you just turned the main screen off by accident. So try screen select: Fn + F-key (with the 2 boxes on it).
And if you are using an old LCD screen, try shining a flashlight into it, to see if the backlight went out. It is very unlikely, but it can happen.