monster with newest update+6pole motor= fail

[Semi Pro]

so i updated my monster max last night with the newest firmware and took my align 600xl powered hotbodies lightning evo buggy out for a run

now any time i go from hard brake to full throtle it stumbles and coggs before going

whats the deal, its only geared to go 35mph, so everything stays cool

this wasnt a problem before the update, any ideas as to what i can do to fix it?