For relays that use invert_relay as True, on output pin setup, there is a short toggle between Low and High that triggers the relay between the original GPIO.setup and the output line that sets the initial state.
The GPIO.setup() has an optional parameter initial to set the initial state on setup.
For relays that use invert_relay as True, on output pin setup, there is a short toggle between Low and High that triggers the relay between the original GPIO.setup and the output line that sets the initial state.
The GPIO.setup() has an optional parameter initial to set the initial state on setup.