You should really call them before you go. I have a Galaxy S8 Active that had the same problem. I called Samsung support who sent me there. When I got there they told me they weren't able to fix my model I had to mail it to Samsung to get it fixed.
Of course they will. That's what they do. Takes about an hour.
I don't believe water damage is covered under your warranty but they will fix it but I believe the has to be out of pocket.
Azsmo
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