Two identical bottles with different alcohol content?

So I bought two different bottles at two different times. Both 1.75L green apple Smirnoff vodka. One was in glass and one was in plastic. Not really a big deal. But I did notice that the glass bottle says 35% and the plastic bottle says 30% and I’m baffled as to why. Shouldn’t any Smirnoff green apple vodka have the same alcohol content? I’m just curious what the possible reasoning could be. Unless they’re changing their bottles and their recipes?