Two iPhone 12 Max Pro Overheating Problems

I am having extreme overheating & battery drainage problems...

Very frustrating! I took my iPhone 12 Max Pro to an apple store to see the problem and was told that there were no hardware issues, so it must be software. My Phone was so hot I couldn't hold on to it, and the battery drains in less than 5 hours without a lot of use. I can't believe it's software because there's not much intense use, just phone calls, and texting.

I returned the iPhone for the exact same one which is having the same issues. Ugh!!

It's pretty ridiculous to be told that there's nothing wrong with the Phone by tech support when the battery is drained in a short amount of time without intensive use, and it gets abnormally hot. I would love to hear from others if this is their experience and what to do about it?

Thanks,