Try wetting the electrodes, or even the entire strap. Even better, buy a conductive gel in a pharmacy. It costs close to nothing, and a tube will hold years. Also try changing the battery in the strap, even if it does not report low level. Often the straps start to malfunction before the battery is really depleted, because the voltage also fluctuates with temperature.
Hmmm. I used the gel before when I got no or intermittent readings. Garmin specificity recommends that Gel is not used. However I just bought an tested a new strap. That seems to have fixed it.
