My idiot occasionally pees standing up for no apparent reason

I am at my wit's end.

My Ozzy is a menace normally but this is just ridiculous.

About a year ago I noticed there would occasionally be pee outside the box, but right next to it.

I have spent a year thinking he was marking or something else behavioral and trying everything. It's to a point now where I clean the box every single time he uses it.

Well, I finally caught it in the act. He literally scraped like normal, and instead of crouching he just casually stood there and peed on the wall behind him. Note: this is the wall of a washing machine. The box was recently moved to my bathroom/laundry room to make clean ups easier.

He finished, "buried" his business and waltzed off like he didnt just projectile urinate on my the side of my washer.

Besides getting those splash guards(which I'm already doing) Does anyone have any ideas why he started doing this and how the hell to get him to stop?