Thanks for all the comments and suggestions.
Answering some of the questions asked above:
"If a breaker how long would you estimate the wire is from the breaker to the Insteon outlet? GFCI device?"
It's a receptacle roughly 10 meters (~33ft) from the Insteon device
"are you certain the query is tripping the GFCI or is the GFCI tripping at some point and the query is discovering that fact for you?"
I'm 100% certain that the query is tripping the GFCI. I have an outdoor camera powered indirectly from one of the outlet (USB adapter to the camera). I can reply from the camera and it literally goes black at 3:00:00am - not a second sooner or later.
"Does the GFCI ever trip randomly ( not during an ISY Query)?"
Yes that happens as well.
"GFCIs are not all created equal. Some older units are prone to nuisance tripping. If it is an older unit you might try replacing it"
I did replace the GFCI a while back.
"Have a look at any outdoor devices that may have degraded over time (transformers, underground cables, smokers, etc)."
So - as mentioned this is in my backyard ie outdoor.
I have ~4 outlets behind the the GFCI outlet. Most outlet supply power to 110VAC->12VDC outdoor power supplies and some of these are behind outdoor smart plugs. While the outdoor plugs and the power supplies are powered the load is minimum - less than a few Watts.
One outlet powers a outdoor access point. In addition I have a couple of USB powered cameras.
I've replaced some of the outdoor smart plugs but haven't seen any difference.