It's interesting how some males act as Soli does, even when neutered, and others don't, even when not neutered.
Spraying is my #2 (after kittens) reason for wanting males fixed. It ties with fighting. I've seen too many cats injured, or had cats run off.
Yes, you have to find it, as it's not pleasant. Does he do it when other cats come in close, such as under the house?
Love All Life, Thank You For Posting! :)