After updating
implementation 'androidx.appcompat:appcompat:1.1.0-alpha02'
to
implementation 'androidx.appcompat:appcompat:1.1.0-alpha03'
locale settings was not working anymore, spent half day to figure out that library was the actual problem.
Is there another NEW way for locale setting or workaround, or is it just a bug in the library and should just wait for another version with bugfix?