Im using legion go and whenever im using the 40watt tdp, my battery sometimes drain and sometimes didn't charge but stay at the current level while charger plug in

Does this happen to anyone ? If so, can anyone help fix it ?

Having a similar issue on my ally. I have to put the device to sleep. Then it wakes up and charges. It seems to happen on my 100w car charger but not my ally charger.

Turn down the tdp, the legion go is not designed to run at 40w tdp and charge at the same time as it is prone to overheating.
i dont have my legion go near me atm but in most cases you want to be at 15-25w IIRC