Bdtyktl

So I have a laptop with Intel HD Graphics 530 (integrated graphics), and I ran into a problem I hadn't run into before and I think the culprit is that the laptop is sending w.e. resolution my laptop thinks is the "best" and just scaling it to match what "I" want the resolution to be (I think this might be a feature update?). My laptop is connected via HDMI to a receiver, and the receiver is connected to a TV. I know my TV is NOT 4K capable, but my receiver is. When I connect the laptop it automatically sets the display resolution to 3840 x 2160... 4K. So it seems my laptop is detecting the receiver accepts 4k and it's sending 4k signal. But my TV does not, and so I just see a black screen (but sound works via the receiver). I tried to lower the resolution of the TV signal, but my laptop keeps insisting on sending 3820x2160 resolution by scaling w.e. it's displaying to what I want the signal to be (frustrating!). I've played with the aspect ratio settings to no success... how do I set my "Active signal resolution" manually?

I've attached a screenshot of what the display says under the windows "advanced display settings" information.

I had the same problem, and for me at least clicking on "Display adapter properties for Display 2" let me pick the right resolution.
I went to Settings>System>Display>Advanced display settings>Display adapter properties for Display 2

(Settings as in the settings you get when you click the little gear icon in the start menu or start typing "Settings" in the start menu in windows 10).

Then, click "List All Models,"

... And my correct active signal resolution was listed, so I picked it and clicked OK. I hit "OK", then Apply, and this fixed it for me.

I have Windows 10 and a LG 29UM68 monitor, displaying only on the monitor.

The solution I followed is the one provided here:
https://answers.microsoft.com/en-us/windows/forum/windows_10-other_settings/incorrect-active-signal-resolution/9ff80937-8959-42bf-acc7-cca8a3bae441

Basically make sure that in the settings for the Intel graphics, the scaling is set to "Maintain Display Scaling." For some reason when I played with this setting it didn't work the first time, but I made sure I set the correct resolution and selected that "Maintain Display Scaling," and the "Active Signal Resolution" matched the "Desktop Resolution."

Edit: This solution worked when I had my laptop display and the external display active (either on duplicate or extend); it did not work when I set my external display as the only one active (here it doesn't matter I correct the resolution when in duplicate or extend, when I switch to external display only it appears the resolution goes to the 4K resolution and I can't change it since I can't see anything.)