One of my techniques for running traps in dungeons is to ignore passive Perception as much as I can.
Passive Perception is a powerful tool, but it is not without its drawbacks. I dislike how no dice are involved as, after a while, it makes everything samey. Instead, if the character would become aware of a trap by triggering it, then I allow them to make the Perception check to notice it first.
Passive Perception is for those times when a character would remain unaware of something afterwards.
— Merric Blackman (@MerricB) September 13, 2021