Question Issue with screen tearing when using laptop with external monitor ?

[Aepoh]

I'm having an issue with a monitor I recently purchased. It's an Acer B247W 24" 1920x1200 monitor and I have it hooked up to my laptop via HDMI, which is an Acer Nitro 5 (AN515-51).
Using the below video as a test, I get bad screen tearing on the monitor, but only under certain circumstances.

View: https://youtu.be/vigX3H7WX5Q?si=ZfLMYt2db5qmLNve


When I mirror my laptop's screen with the monitor I don't get any screen tearing or judder on either of them. But when I have it set to use the external monitor only with my laptop's screen turned off, I get screen tearing, and it's not consistent either. Sometimes it'll be on the black square, sometimes it'll be on the white square, sometimes it will be on the newspaper background. Basically it's just kinda random.

When I first got it and set it up there was bad stutter as well. After updating my Nvidia GPU driver the stutter seemed to go away but I still have screen tearing. I've reinstalled both the Nvidia and Intel display drivers and I've updated Windows 10, yet the issue still persists. I've tested the monitor with my Steam Deck as well and I don't get any tearing regardless of which screen configuration I use, but then again I know the Steam Deck has some pretty sophisticated anti-tearing tech so maybe it's not the best device for me to cross-reference with in this situation.

The only other thing I could think of doing is getting a DisplayPort cable and seeing if that helps. I've already tried a few HDMI cables and none of them have made a difference. The monitor has Adaptive Sync but it won't let me turn it on unless it's connected via DisplayPort. If anyone has other suggestions I'd really appreciate them.

 

[Fix_that_Glitch]

Have you tried using 1080 instead of 1200? What is the refresh rate of the monitor?

 

[Aepoh]

The monitor outputs in 1080v when I'm mirroring it with my laptop since the laptop's screen is 1080v. The refresh rate of the monitor is anywhere from 50 Hz to 75 Hz, but windows only gives me the option of 60 and 75. I use it in 60 but I've gotten screen tearing when setting it to 75 as well.

Tested it again and the horrible stutter is back in addition to the screen tearing. I dunno if the monitor just needs to "warm up" everytime or what but it's really quite bad. I can even see it when typing. Using 2nd Monitor Only and setting the resolution of the monitor to 1920x1080 I still get extreme stutter and screen tearing. I still get a bit of screen tearing when the monitor is set to Extend. I don't get any tearing when the monitor is set to Mirror, maybe a teeny tiny bit of judder but that's it.

 

[Aepoh]

I just realized my laptop doesn't even have a DisplayPort port, so guess that's out of the equation. I'm still not sure what's causing the issue. Maybe vBIOS? But my BIOS is already at the latest version...

 

[Aepoh]

I tried reinstalling my BIOS but it didn't do anything. My guess as to what's happening is that when using the laptop screen itself the computer uses the Intel display driver, whereas when connecting it to an external monitor or TV it will use the Nvidia display driver working alongside the Intel driver to produce an image. So one of those two must be dropping the ball when it comes to displaying to external monitors.

I give up.