I mean this is pretty true of any Star Trek series. DS9 from the 90s probably has the widest gulf between grim and goofy episodes; in one episode there's a war criminal who gloats about committing genocide and getting away with it, and another episode from the same season has the cast playing hopscotch.
They never really resolved the tribble issue. I really want to know if they had to call in the Klingons to help get rid of them again after that episode
Isn't it funny that the events of modern day are hundreds of years past for the members of Starfleet, yet all of their cultural references and entertainment options revolve around our period?