Weird Face ID issue

I had an iPhone XS Max for repairs and there was a shorted cap on VDD_MAIN, Got rid of the short and everything was fine. Until the battery was low and i plugged it in to my Apple USB C Fast charger and it turned on but this time with a pop-up saying Face ID is unavailable but then I un-plugged it from the fast charger and plugged it in to the charger which came with my iPhone and this time there was no Face ID pop-up. Any idea what caused this?