While Meghan was, indeed, forced to learn tons of new royal protocol rules when she joined the royal family, the press heavily exaggerated the amount of rules, especially when it came to how many Meghan was supposedly breaking.
Anyone who followed the royals in 2016 knows that there was a new headline pointing out yet another "royal protocol" blunder Meghan committed almost daily. Harry points out that most of those protocols were fabricated by the press for clicks, with Meghan calling it a "baptism by fire."