Not exactly "didn't work" but similar to Eurus' example.

I made a CR 10 boss baddie with grapples, teleports, and lots of mobility. Then the party's Paladin//Monk started jiggling, Entrancing the boss, and making them unable to move away from said PC. So there went... 90% of their fun abilities.

However! The party befriended this NPC, they joined up for a lot of the game, and on a later encounter, I got to use this peep's abilities. Eliciting a "Whoa what the heck, they just hulked the hell out!" to which I let the party know that that's what WOULD'VE happened to them, had she not jiggled.