To check my search and charts rankings and read user reviews in the US App Store, I use an US Apple ID. If I have been signed in with my personal (German) Apple ID when logging in with the US account, an alert shows up "This Apple ID is only valid for purchases in the U.S. iTunes Store. You will be switched to that Store.". After dismissing the alert, I can view the US App Store.
Since I installed iOS 11 on my iPhone, this doesn't work anymore. No matter which account I'm using, the search results and charts are from the German App Store.
Can anyone else confirm this? Is there a way to view foreign App Stores?