It's a bit more nuanced than that. Essentially AP fact checked it and instead of saying "Hillbilly Eulegy doesn't contain a story about Vance getting freaky with a couch" they used the headline "Vance never had relations with a couch"
That's not something anyone could actually know for sure though, and they were called on it... and had to retract it...
Which of course lead to people wondering why it was retracted, and it kinda snowballed. I don't think anybody seriously believes it, but as the story goes, there's no evidence he DIDN'T fuck a couch lol