My Fitbit Sense developed "technical difficulties" off & on after l began regularly using it to swim laps, 7 months ago. Noting a greater increase in screen issues and questionable data recorded, l decided to use my Asurion Protection Plan to have it repaired. However, following directions required for mailing seems to have actually fixed the device. Customer Service could not have been more gracious when l explained what happened, giving me a time-frame and process to follow, to make sure.