My friends account was hacked?

He told me that a few weeks ago his PlayStation account logged him out and asked for him to sign back into psn but just never did since he wasn’t on his PlayStation for a bit. He told me though that his Fortnite account logged him out too and a kid was playing on his account Because he joined his accounts party and heard the kid talking. I decided to help get his account back so he remembered and put in his password and he was logged into PlayStation we got onto Fortnite and it said he was logged out so we decided to fix that later he was moving around on the PlayStation menu then it logged him out of his account and made him put in his password again so we changed the password to something brand new and it was fine for a bit then it logged him out of his account and told him he was signed out of PlayStation network again. We couldn’t really find anything about this online so we called PlayStation but it told us to go on the website for account help but when talking to the bot it was telling us to do the same things from before. We also tried 2fa but he got logged out before he could ever have enough time to set it up. The only thing I could think of was that someone hacked his account then sold it with the Fortnite account but that might be a stretch. Does anyone have any advice or tips?