Question Laptop internal stream and HDMI out stream pointed at internal display??

Mar 29, 2023
Yeah...I know. But I'm not joking.

This is an Acer Q525U with an HDMI output. Windows 11. Whenever you plug another screen in (tried TV's as well as desktop monitors), the screen shrinks for a sec, then expands back to normal size. The status light on a desktop monitor lights for a min, and then goes back to standby. I've inspected the HDMI socket, changed HDMI cables, flashed the BIOS, updated drivers (intel UHD 620), changed resolutions, refresh rates...nothing changes. I've tried extended, mirrored, "main display" on both. Oddly, when I have the cord plugged in, and the displays set to extended, I have a brightness slider on both...that's the first reason I think it's sending both output streams to the same device. Second reason is that I managed to get some windows open that disappear when you unplug the external monitor, but still show in the taskbar...they wont maximize with the exterior screen unplugged. Plug it back in and they pop up...all on the built-in laptop screen.

I wouldn't have even thought this was possible, but I recently ran into someone that was unfamiliar with connecting PC's. They had put either a VGA and a DVI, or a DVI and an HDMI in the same screen from the same computer, and it acted the same way.

I had to post as a question because it became ...complicated... to try to figure out how to structure a search query for this.

ANY ideas?