I know this has been debated over and over. On one side folks believe that the element soaks up moisture out of the humid air. The ground fault trips. There solution is to plug it into a non grounded receptacle. In my and others that works if it is not a ground to the box. That can be determined with a simple series of tests with a ohm meeter.
Others feel that the GFCI tripping is a sign of a bad GFCI or a grounded smoker. Those arguments are highly debated.
Those smokers that have this problem are usually stored outside under a water resistant cover.
That is where I store mine. I have a very good cover and then place a sheet of Plexiglas on top of it.
My GFCI trips after we have a lot of rain or humidity. This fall we have had a lot of rain.
I figured my GFCI was ok since it would run a 800 watt hair dryer and is only a few months old. It is a 20 amp receptacle on a dedicated 20 amp circuit.
When the GFCI tripped this afternoon I decided to heat the element up with a hair dryer. After about 10 min I could not touch the bare element. It was hot. I plugged in the smoker and it heated like it should.
I am not saying it is a permanent fix but it dries out the element till the situation returns.I think there are only a couple of fixes for this.
I could store the smoker inside but that cannot be done. The other is only a thought. I could use a dehumidifier stick like what are used in gun safes. That might work. You cannot close the box up to tightly since it might mold.
This might be a viable solution for those with tripping GFCI's