I have an older 1080p Philips 9 series LCD tv. And no matter what I tried I could not get it to show my laptop screen. I tried all sorts of settings tweaking on both the tv and the laptop. Just nothing. And I know the HDMI port is just fine because a laptop running win7 works just fine and as does the external TV box.

So in the end having faced defeat and not finding any more usable advice on the net, I dug up an old USB-A docking gizmo and it worked just fine.
It looks to me that something has changed with the Win11 display drivers.

Anyway, hope this helps someone in the same predicament.

Oh by the way, my usb-a dock is so old that google could not find any pictures of it .

Glad you figured out a way to fix the problem. I imagine you tested the HDMI cable and it's fine too. Weird. Far as I know, the HDMI spec is supposed to be fully backward compatible, so even if you have HDMI 1.2 or something cable/output it should still work with an HDMI 1.0 tv and vice versa. Or maybe it's some funkiness with HDCP on the tv? I have a strong personal dislike of "content protection" BS. I bet in some way it's responsible.