Instinct 1000 feet off or more on every ride.

Had this thing for many years, last little while every ride misses 1000ft of climbing or more. The 1,700+ ft of climbing on my last ride came through as 520ft. Even though the graph was accurate and you could see visually the climbing, right next to it the numbers are way off. While I can manually override on Strava using maps is there a way to ignore the altimeter and use gps or the map or anything but the watch? I sure as hell am not buying the new one if the alt. is as useless and having to manually “guess” sucks.