So small update, I just brute force retried a few times and finally got my builds through. Looking a little deeper on the internet and it seems like this is a bug with Apple. The way to tell is that in the first line ITMS-90725: SDK Version Issue - This app was built with the iOS SDK. There would normally have it actually tell you which SDK you built it with (e.g. "the iOS 12 SDK"). If it doesn't just try again. Hopefully they can resolve this soon, resending builds is tiresome.