Ghost Touch in iPhone XS Max

I updated my iPhone XS MAX to iOS 16.5.1 last week. Before the update everything was okay but afterwards Ghost Touch started on my iPhone. As days passed it became more frequent. So I restored my iPhone with iTunes. Soon after the restore, iPhone was all good again but after 6-7 hours ghost touch came back. Now I wonder if it was hardware problem or software? and if it was a hardware problem, why did phone run so smooth after restoring for 5-6 hours straight? Talked to apple support technician yesterday and even they could not find out the problem. They suggested to take it to their service center.

One of their suggest was to get battery relaced. Could it be the cause?

So, I'll do that but meanwhile am leaving this query here so if anyone has a solution, please help me.

PS - iPhone do not have any physical damage or water incident for at least past six months.