Screen doesn't change after pressing a button in Xcode simulator - xcode

Question

My Kivy app work fine in python2. Running in Xcode (10.1) simulator gives me the main screen, but pressing button does not bring me to the second one (drawing screen). Interestingly when moving and pressing on the mouse, the app print the coordinates as it should.
I've tried create a very simple project with only 1 button and 2 screens: again, on python works OK but in the simulator not.
Any suggestions?
python
class MainScreen(Screen):
username = ObjectProperty(None)
test_type = ObjectProperty(None)
test_date = ObjectProperty(None)
def reset(self):
self.username.text = ""
self.test_type.text = ""
self.test_date.text = ""
class SecondScreen(Screen):
pass
class AnotherScreen(Screen):
pass
class ScreenManagement(ScreenManager):
pass
class DrawInput(Widget):
def on_touch_down(self, touch):
timing_ms = ApplePenApp.get_running_app().sw_seconds
print('test')
with self.canvas:
Color(0, 0, 0)
touch.ud["line"] = Line(points = (touch.x, touch.y))
def on_touch_move(self, touch):
timing_ms = ApplePenApp.get_running_app().sw_seconds
touch.ud["line"].points += (touch.x, touch.y)
def on_touch_up(self, touch):
timing_ms = ApplePenApp.get_running_app().sw_seconds
presentation = Builder.load_file("applepen_kivy.kv")
class ApplePenApp(App):
def build(self):
return presentation
if __name__=="__main__":
ApplePenApp().run()
Kivy
# File name: main.py
#: import FadeTransition kivy.uix.screenmanager.FadeTransition
ScreenManagement:
transition: FadeTransition()
MainScreen:
id: main
SecondScreen:
AnotherScreen:
<MainScreen>:
name: "main"
#define global variables
username: username
test_type: test_type
test_date: test_date
GridLayout:
cols:1
#organise the window
size: root.width, root.height
GridLayout:
cols: 2
Label:
text: "Username: "
color: 0.5,0.5, 0.5, 1
font_size: 30
TextInput:
id: username
multiline: False
font_size: 30
Label:
text: "Copy/Recall/Recall2: "
color: 0.5,0.5, 0.5, 1
font_size: 30
TextInput:
id: test_type
multiline: False
font_size: 30
Label:
text: "Date: "
color: 0.5,0.5, 0.5, 1
font_size: 30
TextInput:
id: test_date
multiline: False
font_size: 30
Button:
font_size: 30
size_hint: 0.5, 0.5
text: "Submit"
on_press: app.root.current = "drawing"
<SecondScreen>:
name: "drawing"
FloatLayout:
DrawInput:
id: drawing
Button:
font_size: 30
size_hint: 0.2, 0.05
pos_hint: {"x": 0.4, "bottom": 1}
text: "finish"
on_release: app.root.current = "main"