What often happens in a faulty OEM headlight switch is when an attempt to activate the High beam is made, the headlight shuts off altogether and then, maybe, the High beam turns on. There could possibly be a couple of exciting seconds until the light is turned on when switched between Low and High or High and Low. Sometimes, there is no pause between High and Low. Sometimes, the headlight activation depends upon the amount of pressure on the button; other times there's no telling when it will turn on.
Is that what's happening, pc759?