Instinct Solar altimeter, barometer and thermometer issues

Hi, I've been using the Instinct Solar (Camo edition) for a little a over a year now. The watch has been working great for the past, until starting from one day last week the altimeter suddenly showed extreme readings (around -1400 meter, which in normal condition it should be above sea level), and the barometer showed value significantly lower than the sea level pressure (supposed sea level pressure ~1013hPa, the instinct solar showed 826hPa). So the altimeter and barometer contradicts themselves. (Added: The thermometer is also not working as it shows values in 300+ degree Celsius range)

I have tried manual calibration of the system, which it kinda work, but the extreme value will show up whenever I switched to auto calibration. And even if the altitude is correct from obtaining either GPS signal or DEM during auto calibration, the reading from altimeter never changed back to the corrected value after calibration. When I tried to manual calibrate the altimeter, after setting the elevation to sea level, a warning screen showed up stating that the altitude entered is out of bounds to work with auto calibration. I have tried resetting the watch, but the extremely reading is still there, and the value is still around -1400 meter.Stranger still, when I went swimming after this happened, the altimeter returned normal with correct readings for half a day. Then it goes back to produce the extreme readings, and never returns normal.

I'm not sure if it is a hardware or software issue. Is there anyone having the same issue as me? How can I fix this problem?