My Vivoactive 3 altimeter hasn't worked since the end of July. It worked fine one day, and did nothing the next. I've tried making sure the hole is clear, I restarted the watch, and tried recalibrating through the compass. I also tried starting a GPS activity and waiting 30 seconds before pushing the start button. It's a good 2.5 years old, so I'm guessing it's on its last leg but I'm willing to attempt any suggestions.