iPhone XS - life of it's own

Hi,

I have purchased an iPhone XS less the a year ago, and it worked great until the last month.

It started lately to act weird ( Manley when my phone is locked by sometimes also when it's open ). While I listen to Spotify the music skips on it's own, the app starts working without me pressing the app, my phone calls are hanged up by surprised, Siri always pops up in the locked screen (even when I disable her ) . It basically feels that the iPhone has a life of it's own.

I forced restart ( it doesn't help )

What should I do?

Thank you