I used same example just add inside drawer Textfield then try to focus it will cause keyboard open then dismiss automatically!
I only tried on IOS device I don't know about android if have same issue
drawer: const Drawer( child: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[Text("This is the Drawer"), TextField()], ), ), ),

I used same example just add inside drawer Textfield then try to focus it will cause keyboard open then dismiss automatically!
I only tried on IOS device I don't know about android if have same issue
drawer: const Drawer( child: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[Text("This is the Drawer"), TextField()], ), ), ),