Curling iron compatible inverter

I've never been able to get my girlfriends curling iron to work off the inverter. The load isn't too much for my inverter (only about 200 watts), the light on the iron goes on but it just never heats up. Could this be because of the modified sine wave some inverters produce or possibly undervoltage or underfrequency ?

Again, this is NOT having enough amperage output from the iinverter as the iron never even attempts to draw any current.

Thanks for reading,