[Bug] Pokemon GO is 'Not Compatible' Anymore

I'm on a Galaxy S6. I guess this is a bug, I don't know for sure. I was playing Pokemon GO yesterday, and it worked just fine. But when I updated it (today) it's not working. It starts loading then says "This device, OS, or software is not compatible with Pokemon GO." I've looked up how to fix it and it says my phone needs to not have root, so I downloaded a root checking app and it said I don't have it. My brother, who is on an older OS, can play it perfectly fine. I'm not quite sure what's going on here, but all I really want is to go out and catch some Pokemon.