Two times now I've started ride with a green GPS status but no distance at all has been logged at the end of the ride. I haven't been paying attention to the screen in these miserable dark winter conditions so I haven't noticed it during the ride.
Both times I've started the device from standby status and waited until GPS bars are green and then started the activity. The other time I put the device into standby and started it indoors, yet the device claimed to have GPS lock.
FW latest, 9.73. In attached pic I started device indoors with definitely no GPS signal but still green status.