As an added data point, I’m having a similar issue with chargers that can’t deliver enough power. This is with an AMD 7640U, BIOS 3.03, and Fedora 39.
The charger that I use works perfectly when I use USB-C slot 1 (which always delivers at least 45W), regardless of whether other devices are plugged in. When I plug in to USB-C slot 2 (which only delivers 20W when slot 1 is in use) while another device is charging from slot 1, it fluctuates between charging and not charging every couple of seconds.
When I found this thread I decided to test with a couple other chargers that were lying around. My brother’s laptop charger, which came with a Thinkpad from a few years go, works well, showing a draw of ~60W on a KillAWatt. A 20W Apple charger that came with an iPad does not work, delivering a little power (~1.5W) then dropping to 0W. This charger tries to work, but fails–it fluctuates between ~2W and ~8W with an eyeballed average of ~4W and causes the battery light to cycle on and off every couple of seconds, just as with slot 2 of my charger.