Is there a way to disable "detecting device?"

So my mother has a Samsung UN55CU7000DXZA 55" TV. It is a "smart" TV, but the smart features are not used and it is not connected to the internet.

We have an old DirecTV box (Model H20-600 if that is of any help, not sure why it would be) connected to it, and that is the only input device. Issue is that every time the TV gets unplugged, the DirecTV box gets unplugged, both get unplugged, or the TV for whatever reason accidentally gets switched off of HDMI1 (it happens, there are multiple people using it who get confused easily,) it goes through the "detecting device" thing.

I can hit the down arrow to skip it and set it as a PC, but that (a) locks out a bit of picture settings, and (more importantly, B) puts a black bar about 1/2" tall at the top of the screen for some reason (yes, everything is set correctly resolution and aspect ratio wise.) So, what always has to happen is that I have to sit and wait for it to try to detect the device, fail to do so, and then select "set up later." Then, and only then will it work as it should.

This bothers me, but I really don't use this TV much, but the other people who see this get all freaked out and start mashing buttons when it happens, so it is an issue.

I have equipment control, anynet, and CEC turned OFF in the menu, which you would think would make it not do this nonsense and just behave like a normal TV, but this "smart" TV seems to just be too dumb to work as it should and just display the signal sent to it without interference like every other TV on the planet seems to be able to do. I don't know, I would never have bought it, but here it is and sadly because it is in the house I am technical support for it.