Did iOS 18.6.2 update cause my phone to overheat?

After updating to iOS 18.6.2 on my iPhone 12 Pro Max, my phone screen doesn’t respond or glitches out constantly. I realized that this was due to overheating since my phone is hot to touch after normal use.

I have had my phone for 4 years now and recently replaced the battery 1 month ago. The battery replacement was due to capacity under 80% but there was never issues ever with overheating. The phone ran smooth as normal and was even better when the battery was replaced. However, since the update, the phone is unusable when I use it normally since the phone screen would turn off and overheat.

I have found what works is I have to take off my phone case and use the phone on a surface to avoid additional heat. Is this caused by the update or is this a combination of phone age and battery replacement? It just seems like too much of a coincidence that my phone overheats now only after the most recent update… Any help is appreciated!