The trouble is, Honey that Jonny feels he can't mess around and be the joker of the house because when he did that before he was nominated for eviction, and he's deliberately calmed down since then.
He and Kate do get on, but I wouldn't say they're close, not like Jonny and Alison were. And Kate's only really spent more time with him since Spencer left.
Hopefully we'll soon see a cheerier Jonny again, especially if (? when) the bars are removed.