Doomfist vs. Bastion in Sentry Mode

Hi Blizzard,

is it expected behavior that Bastion while jumping on a jumping pad (like you find them in Chateau Guillard) is immune to the knockback effect of Doomfist’s rocket punch?

I had a Bastion who jumped onto the jump pad and reconfigured to Sentry mode so he stayed in Sentry mode while just jumping up and down using the pad. I was playing Doomfist and tried to Rocket Punch him and though dealing damage to him, Bastion moved not a single horizontal millimeter although it should have pushed him off the cliffs.

Bug or feature?

Kind regards
fx