Solution found, closing thread after I write this. Might be shadowbanned or something, who knows. Nobody's replied to this thread yet over the course of a week and I got a bunch of automated messages from Dell Cares, and no replies when I sent them the information they want.  A BIOS update whipped my USB-C port back into line, and plugging into a Dell Dock with Thunderbolt charging may have helped reset it, so to anyone that reads this, find someone with a powered (unsure about unpowered) Dell Dock, it may help. It now charges off of 65W Power Delivery and can handle my USB-C drive just fine with no external power. Here's hoping it doesn't break again, but I've used my setup (65W GaN II Anker Nano + uni 10ft USB-C to C 100W cable) for a few days with no issues so it should be fine. I'll unmark this as a solution if I run into trouble again. 
Hey there everyone! I've got an m15 R4 (i9, 3080) laptop. I carry this thing to school and don't want to keep my screen dimmed through 6 hours of work, so I've recently looked into some PD (Power Delivery) chargers after some specs showed me that Thunderbolt also supports PD and some Dell manuals and support documents proved it. I bought a 100W power adapter under the belief that it would draw as much as it could, and forum posts show that XPS devices could pull up to 95W from non-Dell sources, so it'll probably work, even if it's locked at 65W being a system before the change. It even has a little plug icon next to the TB icon, so I'm pretty sure it takes power. I don't mind turning it off and twiddling my thumbs for awhile while my laptop resuscitates itself through the power of a tiny GaN charger. To top it off, XPS devices frequently come with Dell's own USB-C chargers and have 30-series cards that eat as much power as mine does.  It worked for about two days - my BIOS recognized a 65W charger (so I returned the 100W and bought a 65). My laptop would slow charge, and if I was using it, Windows would note that it was plugged in, and either charging very slowly, or not charging (but not draining my battery). I even tested Dell's thunderbolt tech - my public school apparently has loaded pockets and bought everyone an XPS 15 and a powered dock to go with it. When plugging in, the laptop started charging. For those two days, I didn't have to concern myself with dimming the screen and keeping tabs to a minimum to sip power.  Then, it all stopped. BIOS still recognized a 65W power adapter when I plugged it in, but there was no charging. Windows refused to take notice of the adapter. I had my Thunderbolt 3/USB Type-C single-port setup plugged into my PC at the time for productivity, so it wouldn't be a few days before I plugged in and the port didn't register anything. I checked to see if the hub was overloaded, or if my keyboard stopped working in between, and it turns out the hub didn't even power on, there was no power out from the port. I tried reinstalling drivers, and disabling and restarting through Device Manager to see if I could fix that port, with no luck. So, now I have an Alienware with a broken Thunderbolt 3/USB Type-C port. How do I fix it? Thanks in advance! Things I've tried: Things that I have not yet tried: TLDR: tried USB-C Power Delivery on my Alienware after documents showed it could be done through thunderbolt. Worked for a bit, then stopped working, and the port itself seems busted too. 
m15 R4, Thunderbolt 3/USB Type-C busted after PD usage