The only time I noticed my device heats up when on the same day I updated the device, charging while using the device or playing games. It could also be because the weather is warmer now? Whenever mines would heat up, I put it on top of my air purifier that vent out cool air at the top. Have you turned off your device since you upgraded? Now, after updating, I would turn my device off for a few minutes and it doesn’t heat up as much or has less glitches.