It's probably not the update. This is a common failure mode for both the EVSE and the car's charger. What does the charging screen say when it's charging at 16a? There's two numbers separated by a slash like 32a/32a. The first number is the amount the car is drawing and the second is the amount the EVSE is advertising. If the second number is 16a, then the EVSE is throttling the charge, if the second number is 32a, it's the car.
A couple more things to try, after the car has been charging at 32a for 20min or so, stop the charge, pull the plug from the wall and feel the blades of the plug. If they are too hot to handle, there's something wrong with your outlet. Warm is fine, HOT is not. Also try charging at a different EVSE, or having someone else use your charging setup.