Iphone se 2020 heating up in very less time after 10 months of Usage

I have been using my Red Iphone se 2020 for over 10 months now. I have never faced heating issues on my phone except in gaming in some cases which I rarely do. But since the last three weeks(after updating to ios 14.7.1) I have been facing a lot of heating issues mainly below the camera and on the side. I have tried all possible ways to resolve the issue but nothing worked. I have even reset the phone but the heating is still there. On calling an Appe representative ,he ran a diagnostics but he didn't find any issue .I took the phone to an Apple authorised service centre and after examining the device they told me that they didn't find any 'significant' heating and unless the device shows the temperature warning on its own they can't process it further. But even after watching a video on safari for 9 minutes, the device is heating to such an extent that it feels uncomfortable to hold in the hand. I had only installed whatsapp and Gmail on my device. A video call for just 2 mins produces such effect. The touch Id sometimes feels warm to touch. I am using the device without any cases on it. I am really worried about my device and don't know what to do and whom to consult for any further assisstance. My battery health is now at 91 .Kindly help !