i pad pro m4 11" heating while charging

It is not unusual for an iPad to become warm when charging or being used - more so when using some types of iPad case. High screen brightness and/or CPU intensive Apps will also create more heat.

The key point is that whilst your iPad may become very warm in normal use, the iPad should not become uncomfortably hot to handle. If your iPad is becoming too hot to hold, you should take your iPad along to the Genius Bar at your local Apple Store - where the technicians can examine and test your iPad for faults.

Genius Bar Reservation and Apple Support Options - Apple

If you have any concerns whatsoever, you would be well advised to visit the Genius Bar at your local Apple Store as previously recommended:

Genius Bar Reservation and Apple Support Options - Apple

Assuming that your iPad was purchased directly from Apple, you have 14-days within which to unconditionally return the iPad for exchange or refund. Upon expiry of 14-days, any faults will be addressed under warranty.