Elevation recording stopped during ride.

Rode yesterday from sea level up the Haleakala volcano in Maui Hawai’i.  My 530 tracked the elevation perfectly on the way up and for a few minutes down from 10000’ to 8000’. The elevation recording then flat lined at 8k’ and didn’t measure rest of descent which is basically a mirror image of the track up. It was raining heavily when the recording stopped. HR and speed worked fine the entire ride. Wondering if water can 530 elevation or other ideas for fixes.