Region3 not picking up position change on server

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1 
while wait(.1) do
    
    local RowBoatAir = game.Workspace.RowBoat:FindFirstChild("RegionTest")
    local regionRowboat = Region3.new(RowBoatAir.Position - RowBoatAir.Size/2, RowBoatAir.Position + RowBoatAir.Size/2)
    local parts = workspace:FindPartsInRegion3(regionRowboat, RowBoatAir)

    regionRowboat = regionRowboat:ExpandToGrid(4)
    
    game.Workspace.Terrain:FillRegion(regionRowboat, 4, Enum.Material.Air)
end

Ok so I’m trying to achieve an effect where a every water terrain inside of the region 3 disappears, but for some reason it doesn’t change it while tweening. Anyone knows why? Both the tween and the script above are running on the server.