May be some more elements…
I just get this charger : Amazon.fr
and some cable: Anker 140W rated and the 240W from belkin: Amazon.fr (In fact 2 of them 1m and 2m)
This charger have a 140W USB-C Port and 2 other limited to 100W.
The 2 low USB-C work as expected at 100W with all 3 cable.
The upper (140W one) work @ 100W with a Anker battery, @60 with “standard” cable on the fw16.
But with any high rated cable (140/240W) it togle on/off like with the 140W battery…
(the mesure show switch from 20V/5A to 0V/0A end back every ~second)
So for my it look to be the same “issus” like with the 140W anker battery.
(Note: I have “old” anker 737 battery and charger with max 100W charging that work as expected. And this “old” battery charge at 100W on the 140W port.)