touch keyboard turns on automatically

disable tablet mode first from the quick setting when you swipe from the right side of the screen

and

go to settings> devices> typing> turn off “ automatic show the keyboard in windowed app when there is no keyboard attached to your device “ if that didn’t work

go and repair the soft keyboard software in the control panel

search program and features from cortana or navigate to control panel > programs > and search for the keyboard right click on it and you should see option to repair and uninstall

repairing will set it back to default factory setting