@brindledogs - I have had Basenjis since 1990 and never had an issue with house training, all have been very easy. And I have never had an issue with males marking regardless of in-tact or neutered. I have had females that will mark, but not that often. And at his age I would not say this was a case of marking....
My Male Basenji has peed on my bed and the spare bedroom bed. Where my nephew sleeps when he is in town. I am pretty sure he was marking though. I was keeping a 2 yr old female child at the time and she had been asleep in both beds. And he peed in the spots she slept. But he has not done it since. Vet said he would grow out of it. But I don't know if he grew out of it. Or just got used to the little girl being here.
@wynette - when I place my one pup with a family... she would pee on their son's bed... clearing she was marking it as hers... once they (on my recommendation) to stop her from getting in his room (he was 10yrs at the time) it totally stopped... so consider what exactly is going on.. If I am reading this right, he is in the same crate as another dog? Consider separate crates...
@tanza the vet said as long as my other dog is ok with it it should be ok. Ever sense I got him as a tiny little dog he’d do the basenji dying child sound and I put my other dog in there he goes right to sleep no sounds. They are both ok with it and it’s a giant crate!