Umm... I need some litter training tips...

I have 3 cats--- actually 3 of them are litter box trained.

But somehow my male cat started pee at the front door. We try mop the floor with those floor cleaner so that the smell doesn't stay.... Yet he still does it again and again.

AND NOT ONLY THAT. He kept peeing on my papers... A4 papers / books and bags on my floor in my room. He did not pee on my carpet in my room.. but rather.. papers or books! THen I had to close my room 24 /7...

Everytime I find him peeing at the wrong place I would take him to the litter box. But he wont pee there. He only poo there.
It's kinda frustrating. When he first came he does use the litter box....