Dead device a week after battery replacement.

I used an iFixit kit and followed a guide here about a week ago to replace a poorly performing battery. After buttoning it up everything worked fine. I ran a calibration cycle and had multiple days of normal use. Suddenly today I pulled it out of my pocket around noon (probably had about 50% estimated charge) and it was unresponsive and cold to the touch. Here's what I know:

• If I put it on a wireless charger the wireless charger blinks enough for me to assume that the battery is attempting to negotiate with it
• If I use a known good 65w charger (UGREEN) and multiple high quality USB-C cables, I can get it to show a gray battery on screen with a lightning bolt in it, but after multiple hours it doesn't seem to produce a charge. The phone is slightly warm near the charging port. If I take it off the port it 'dies' (loses the little battery indicator) instantly
• If I try and put it into fastboot nothing happens, except that the battery indicator will sometimes go away, so maybe it's discharging faster than it's charging?
• If I hook it up to my Linux machine with dmesg running, it doesn't seem to be negotiating anything over USB :(

I like to think I'm generally pretty competent when it comes to working with electronic components. The only thing out of the ordinary with the battery swap was having to use 99% IPA to dissolve the battery adhesive, but I was conservative and it was completely dry before reassembly. I'm skeptical about the battery just being disconnected given the nature of the connector, but I'm open to cracking it back open if it comes to it. The bigger issue is that it leaves me phoneless for quite a while which is rough for 2FA.

Thanks