Is it just me or the difference between recommended and expert difficulty quite big?

I’ve been playing since the start on expert cuz honestly i wanted a bit of a challenge, and some time ago i was finishing halo peak, and after not beating the final boss for a good week or so i got frustrated and switched to recommended, then i smoked the boss, didn’t run out of healing, didn’t go bellow half health, the game was like it was on easy mode, has anyone else experienced this?