iPhone 12 touch sensitivity issue and mic problem

My new iPhone 12 has a touch sensitivity issue. If I touch slightly then the touch is not recognizing rather I need to touch with some pressure. Is this problem being faced by anyone else? Or my iPhone has some touch problem?

Also when in call, the microphone sensitivity randomly ups and downs, sometime even it switching between rear mic and bottom mic to capture my voice over a call. Especially happening when there are little background noises. Is anyone noticing the same?

My current OS version is iOS 15.0.2 and bought this phone just 1 week ago.