Q1: Why does the phone get hot when it's charging?
A: This is normal, because the phone will generate some heat when it is charging. However, the main reasons for the heat are as follows:
1. The charging speed will be faster when the phone power is low, the wall charger will output 9V high voltage, and the phone will generate heat because of the voltage converting process.
2. There are too many programs running in the background of the phone, causing the phone to run at a high load and generate more heat.
1. Clean up the running program of the phone with high power consumption in the background in time.
2. Don't play the phone while the phone is charged with low power, otherwise the phone will be in a high load state.
About the error message "This accessory may not be supported by device":
The message would appear if you were using a non-Apple wall charger or in poor contact, but even if you are using an Apple accessory, the error can also happen for the firmware problem with iOS.