Asus ProArt PA248Q and Dell XPS13 video waking

This is a very, very specific situation... but posting in case it helps someone else. You never know. I won't be DenverCoder9.

When I got the Dell I was struggling a bit to find the right cable to hook up the monitor. That USBC stuff was all new to me. So I got a DisplayPort cable and set the ASUS to use that.

I pretty much never shut off a laptop at night but just leave and let it go to sleep mode on its own. But I began to notice the monitor turning its backlight on and off, frequently but not always regularly. And it was bright enough that when I had insomnia (rather frequent starting around 2018) it would really annoy me. 

There must have been some signal coming from the XPS13's USB port that was enough to wake up the ProArt, but obviously since no actual video data were sent, the monitor would go back to sleep. What I was seeing was the ProArt's power light going from orange to white (active), the backlight would go on, then after a moment a little window would come up with "No Signal" and everything would shut off. All the USBC ports caused that behavior. 

I could unplug the monitor from the USB port but that didn't seem like an elegant solution. I bought a USB on/off that was actually meant to turn off the USB port on a Raspberry Pi, and that did not work at all. I bought a switchbox that was supposed to allow two computers to share a monitor, figuring that I could just switch the monitor to take its input from a nonexistent computer. That did not work at all either. 

Then while dicking around with the monitor, I accidentally set its input to the VGA port. And got totally stuck because there was no VGA signal, the monitor wouldn't display the menu. I had to RTFM to get it back to taking input from the DisplayPort port. And that's where I found the solution to my problem.

Just above the power button is the input selector. Its icon is an oblong with an arrow pointing into it. Clicking it cycles through all the input ports. All I have to do is tell it to take input from something that's not DisplayPort, and since there's absolutely nothing coming in there, it never wakes. It seems to be easier on the XPS13 as well, since unplugging the external monitor would cause the laptop screen to wake up and display. Now it just stays black. 

It's nice to solve stuff without having to spend money....