Don’t fucking nerf the core of a character’s mechanics midgame

Happened to me once. Built a monk specifically for cool grapple movement interactions because I hate the standard “I attack. You attack me back.” attritional gameplay that DnD normally has.

Stunned a guy, used my 2nd attack as a grapple, started running up a wall, which both me and the grappled target will fall off at the end of the turn (but I have slow fall, he doesn’t). The GM says:

“You’re running up the wall with the guy still grappled?”

“Yes. Perfectly legal according to the rules”

“You’re grappling an orc fighter”

“Yes. And?”

“He’s pretty heavy… Roll me a strength check”

Cleared it up after the game, but come on man. I explained how my character would work in combat beforehand, don’t nerf me midgame.