Hello.
I think it's beta bug.
Yesterday, I archived my app and release TestFlight.
All of testing is well. My app minimum iOS version is iOS 9.
Today, I've archived same the build and TestFlight but the app show note minimum iOS 11. I tried 3 times upload but show same that note iOS 11.
There is no change any code or update tool environment.
All issue happen after annoucing apple developer beta 5 Aug 0811.
I hope this issue resolve soon. Thanks.