Anyone had problems with intermittent optical HRM (more off than on)? Mines been playing up since about Wednesday. Looked back through Garmin Connect data and it's been hit and miss since then, recording non or very little sleep and long periods without any HR data. Sometimes works if I take it off and give it a clean but not for long. Watch is 3 years old and this is the first problem I've had with it.
I wear a chest strap for training / races but I think a lot of the other metrics rely on OHR so I'll be more than peaved if a £550 watch has failed after 3 years!