My 3-year old (otherwise still perfect) Edge 830 has been producing some very strange behavior for the last couple of weeks: during a ride, the screen sometimes starts jumping wildly on its own, opening menu options, changing screens etc. It's similar to when raindrops drive the screen crazy, except it happens in perfectly dry, sunny weather, without anything (not even sweat drops) touching the screen. If I lock the screen, it sometimes gives repeated messages asking for a manual unlock, so this behavior is still trying to force the random flipping even if it's locked (i.e. the locked screen prevents it but registers some kind of ghost touch attempts). I've already tried a hard reset and it was better for 2 days, but today it happened again once during a ride. Garmin customer service told me this is not a well-known issue, so I wonder what I should make of it. Is it a software bug? Or could it be a sign of some hardware-related issue with the display?