Iphone 15 pro max overheating battery drain and turning off suddenly

I got my iPhone 15 Pro Max about a month ago and I only charge it using the 20 W charger and the cable that came in the box. I don’t use it while charging, about a week ago the phone was at like 6%. It turned off completely and when I turned it back on it was at 3% then two days ago it was at like 79 or 80 and it turned off and on alone no notifications or nothing and when I put it in the charger, it becomes hot today. I took it out of the charger at 5 AM. It was at 100. I put some music on in the car ride for an hour and a half it was at like 92 which is pretty weird. I noticed it was pretty weird, but I thought it was like something that happens once in a while then I went into work. I just went to a couple of TikTok‘s and all of a sudden it was like 64%. I was shocked and I like 10 AM it was like 44%. I put it on low power mode and now I’m at like 12% it’s 1 PM , this is very bad considering. This is a new phone it’s not even been used for like a whole month. I’m on iOS 17.1.1 it’s the 256 GB blue titanium. Can someone help please?