Of course it’s good to take him to a vet if you can, just in case.
But my 1.5yo cat does the same and is also neutered. Before neutering this was everyday and night. After neutering it is sporadic and I think it has to do with my building having two female cats. And this got more intense after I switched him to neutered cat food.
Also, his brother never had this issue before or after neutering. So I guess he just has a lot of testosterone maybe.