Samsung gear s3 frontier not water resistant

I bought a samsung gear s3 just over a year ago and almost as soon as the warranty expired I am having problems with the watch. It sometimes doesnt charge and sometimes switches off. After giving it to Samsung for repairs they contact me and say that the board has been corroded. I do not understand this as it is supposedly water resistant and the only water that comes into contact with the watch is normal sweat when I exercise.

I wouldn't recommend this watch to anyone