The left switch is a 3 position switch. Sounds like the switch is defective. Should stay in one of the 3 positions you move it too, Left - Center - Right.
You need to be a bit more specific.
Which "toggle" are you referring to?
Is it the the joystick? In which case it should be sprung to the centre.
Is it the Switch at the top of the remote? In which case there is no lock that I am aware of.
Thanks.
None of the controls should stick.
If you panic for example, you should be able to release both sticks, both sticks will spring to the centre, left to right and up to down, and the P3 should go into an instant safe hover.
Your controller needs to be replaced for your safety before you lose the drone and or hurt someone.I suggest you dont fly it.