virtual joystick not working in fc mobile

i can't use the virtual joystick in fc mobile properly and also when is start the game it works for a few second and then the cursor just gets stuck when i try to move it it also like lags in the home screen when i swipe left or right to see the events it just gets stuck and then i have to force it to move and i dont think its screen touch problem because my phone works perfectly fine  after i close the game