Mainly because the capacitor on the main board of your charger is damaged, and it is falling off at the same time, resulting in a slow charging, you can go to the after-sales service to let the staff repair you, you can return to normal.
This is because there is a problem with the fast charging controller in your charger, you can directly go to the after-sales service, let the staff replace the controller for you, and then you can charge normally.