the right front cook top element stopped working replaced it the new one, gets hot but cuts out under high demand. Now the front right one is not heating as hot as it should either? Control board issue?
That's very strange, replacing one burner should not effect any other burners.
I really don't know the cause of this problem, I've never seen that happen before, hopefully another tech that has seen this problem before can shed some light on it, if not then you'll need to Contact LG to come out and see what's going on.