GFI is "Ground Fault Interrupter". They are designed to trip when the current in the hot leg of a circuit is not identical to the current in the neutral leg of the circuit.
It presumes if there is more current in the hot leg than in the neutral leg, the missing current is flowing through a person. The GFI then disconnects to protect the person.
If the plug and or the persons hand is wet, and contacts the plug hot or neutral pins while unplugging, that could cause a trip.
Some older GFI's were sensitive to strong near by radio emissions. The emissions could come from arcing as the appliance was disconnected while still turned "on".
The transfer switches in some RV's may emit radio frequency noise. Better GFI's do not do that.
Florescent lights would often trip older GFI's because they often emit radio noise.
Solid state control circuits may cause a radio noise trip. The curling iron may have a cheap solid state control.
Currently the National Wiring code also requires "Arc Fault Detection". Arcing any where in the circuit could cause a trip.
And of course, defective GFI's may trip when they should not.
I wish you good luck and happy trails ahead!