I'm assuming you've watched the classics: The Leftovers, Station 11, et. al.

Have you watched Maniac on Netflix? That;s the closest analogue I can think of if it's the quirky, likable characters stuck in a messed up world aspect of Severance you liked. If you liked the highconceptness/semi-thriller thing, you might want to try Counterpart (Starz?).

Oh...also Homecoming on Prime is a must watch... at least Season 1 is.