Had same problem. Called support and they are sending me a new watch. I agree. Everyone needs to call and complain. They apparently are not reading these forums because the support person had no idea about this common bug and even had to go find a 235 to test and confirm that hers did not have a delay to lock on HR (probably because she had to power it up first.) Eventually if they keep sending out new watches, someone higher up may finally decide that fixing this software bug is cheeper than sending out new watches.
I have had this watch since it first came out back last November. HR worked great at that time but has gotten worse and worse with each update.