When having smeared joker, clubs and spades are "count as" the same suit, therefore "clubs' other suit" is hearts (aka diamonds). But in game seeing double works even when you play only one card of clubs/spades with smeared joker.
#Smeared "Any other suit"
median raft
uneven pumice
This is not a bug, with Smeared joker, all spades or clubs are counted as both spades and clubs, so playing a single black card means playing both a spade and a club
We could argue that the wording of Smeared Joker isn't perfect, but it's hard to make an accurate tooltip that isn't too long