It could be in the process of regularizing. There's no particular reason why "it's" can't be both things. Language changes.
One I've witnessed in my lifetime is "different than" vs. "different to". I was taught the first one. The latter sounds wrong to me, which is why I notice I'm hearing it more and more. (Note I have phrased this subjectively; I'm not saying it is wrong. I'm generally a descriptive grammarian. But it does sound wrong to me.) It may be a dialect thing, in which case my dialect seems to be shifting. Languages change.
One I've witnessed in my lifetime is "different than" vs. "different to". I was taught the first one. The latter sounds wrong to me, which is why I notice I'm hearing it more and more. (Note I have phrased this subjectively; I'm not saying it is wrong. I'm generally a descriptive grammarian. But it does sound wrong to me.) It may be a dialect thing, in which case my dialect seems to be shifting. Languages change.