Hi!
First off, you WILL be able to get him litterbox trained. I promise! However…..as you have other pets, he may not quit leaving his poop everywhere to mark his territory. Here is what worked for Lolli:
Her pen was located on an area rug. When she’d pee and I caught it, I’d sop it up as best as I could and then leave it in her litterbox. I had given her an old pillowcase to lay on/play with that I ultimately had to take away because she kept peeing on it instead. To this day, she will pee on fabric I give her in her pen. So start with the paper towel.
Is Yavin in a pen or a cage? If he’s in a cage, I do recommend a pen as well.
Ahem…do not put bedding all over the cage. I did this with my first bun Eddie and got SOOO incredibly frustrated because he’d poop and pee all over his cage. And I’d get the “DUH mom!” look from him. So if he’s in a cage, keep any litter/”bedding” (such as carefresh) in his litterbox only.
Last but not least, if you are keeping his hay separate from his litter box, try putting some on his litter and see what happens. I was so against this at first cause it’s just….well, gross. lol But rabbits really do like to eat and potty at the same time. I was getting frustrated with mine because they’d pee when they were at their hay box….OUTSIDE the litterbox. So after more frustration, I finally gave in and no more peeing. Really…they can outlast even the stubbornest person.
As for the poop, all you can do is keep picking it up and putting it in his litterbox. But like I said, he will most likely continue to leave poop in places for territory purposes. Lolli knows that she needs to do most of her pooping in her box. But she still leaves them around her pen. I gave up a long time ago and settled for her not peeing outside her box. LOL No really, she is really good about her habits.
Some rabbits don’t like to climb or hop. Lolli doesn’t like her feet off the ground. I am sorry. I am not familiar with you guys! Have you had him long? If he didn’t like to hop up/climb before his neutered, then he won’t do so after. But if he did, he is probably sore and doesn’t feel like it. 