So _that's_ why my monitor doesn't wake up.

I got the new xps13, it only has thunderbolt/USBc-C ports and it's pretty much 50/50 whether my external monitor will wake up.

I figured it was the cable and was about to buy another one but you saved me the trouble.

I also got a hootoo adapter that's supposed to support power delivery but that hasn't worked either :/

This isn't just a problem with USB-C. There are also tons of video adapters on the market that say they support 4k, but really don't. We have grips of 2560x1440 monitors at work, and they had tons of issues like this where the monitors may or may not wake up, may handle the native res for a while, then power down or switch back to 1080p. The only consistent fix for them has been to buy one particular brand of adapter that we found works and making sure it's active. So I guess what I'm saying is, display tech has already been having issues for a long time with crappy components, and USB-C is just adding one problem into the mix now.