I’ve had this happen a number of times and find it really annoying. I don’t even have the English US Language installed, though I suspect you can’t truly uninstall it. I’ve always previously put up with this issue when it has occurred and eventually rebooted to fix it.
Today, I finally worked out how to switch it back. Simply hold down “Windows Key”+Spacebar (Seriously intuitive Eh?) and you get a pop up allowing you to switch between the keyboard layouts.
Clicking back to “English United Kingdom” sorted the problem. I still don’t know how I set it to English (US) though, given I don’t have a language bar and don’t have English US (or anything else) even as an option according to Settings / Preferred Languages.
Anyway, hope this might help someone else being driven mad by this!