Wake to raise

My iPhone 12 pro Max was frequently not turning the phone on after the raise, & ‘Raise to wake’ is turned on, but it still completely stopped responding couple of days ago, so I hard rebooted my iPhone & it worked just one day. I know it is a hardware issue, but I don’t know how serious it is & whether or not if I need to or should send it to Apple store to take care of it.

Anyway, I bought the iPhone from online Apple store few months ago.

Thanx for all the responses in advance!