So there's been a weird development in the saga of my "broken" Switch.
So like I said, I have two docks and two AC adapters (I sold the first Switch that broke but kept the accessories). When this issue started, the first thing I thought to do was test using the other dock and power cord, which is why I believed the Switch's USB-C port was broken.
But just two hours ago, I decided to give it another shot and.... it charged to 30% before it stopped charging.
And just now, I found out that if I unplug it from the power strip (actually a UPS, but I've got the Switch plugged into one of the non-battery backed ports) and then plug it back in... it continues charging.
And yes, it does this with both AC adapters.
I also felt it was prudent, at the times when the AC Adapter stops working with the Switch, to see if it also stops charging any other USB-C devices I have, and it turns out... that's exactly the case.
So now I'm thinking just one of the ports on my power strip is bad, so I make room and try a different one.... but nope.... Switch is back to not detecting it was plugged in (and this is a port that had previously been powering a device, so I know the port itself works).
Incidentally with both docks, if I put the Switch in, it'll eventually do that thing where the green LED blinks a lot.
So I'm guessing all that happened is the USB-C port was in what I've heard people call a "sweet spot." I've seen this with broken charge ports before, where sometimes the pins align just right for them to work like they used to. It's awesome when it happens but its not something you can count on.
EDIT: So....the problem changed. Apparently now charging works just fine, but now neither of my docks will output to TV. Sometimes they don't even detect the Switch, sometimes they act like they're gonna (the Switch's screen goes black, the dock light comes on) only no picture comes to TV. Sometimes they go immediately into blinking light mode... sometimes they act normal then only go blinky when I remove the Switch from the dock.
And yes I've tried both my (official) AC adapters and different HDMI cables including one brand-new unopened cable. It's like this Switch is magic, one problem just healed itself but another took its place.
Also sometimes the system does not want to turn on unless I'm holding down power and volume down. Still, at least it DOES power on and has enough charge that I could transfer my account to another unit now.