I very similar had problems with the 61W (A1718) on my 11th gen so it does seem like it might be an issue with it and the Framework, at least 11th gen.
I’m not sure if it cause the problem but shortly after trying the Apple charger I noticed overheating/bad(?) MOSFETs. I encourage you to look for the issue described here [IN TICKET] Piece of mainboard partially melted. It might be an issue that only presents with extended high load so might be worth running some stress tests and do so with power on the left (right hand side MOSFETs are on the underside of the board) so you can easily see if the plastic shielding gets melted.