This has only happened 3 times in about 2 weeks. Most the time I'm at a table so end up having the charger plugged in as I'm using the Pro 4 and there are no issues. I've noticed if I use the tablet when not plugged in and the battery drops to around 20% and I then stop using it and just put it to one side to recharge I can hear the fan come on after awhile. Just now I heard it and went to unplug the power, I noticed it was very warm and switched it on. There did not appear to be anything intensive running and battery was at 99% full. Ambient room temperature is 13°C. The Pro 4 was on a sofa so effectively had insulation under it. Pretty sure it was on the sofa the last 2 times it happened as well. I will of course no longer charge it on the sofa but is it normal to get warm when charging? I'm new to tablets so not sure if this is normal or not.