I read a previous question regarding a GFCI outlet and a washing machine, but my issue is slightly different.
I have 2 GFCI outlets in a washroom in the downstairs of my home. One is obviously feeding power to the other, as well as an additional standard outlet (directly) above the washroom in my daughter's nursery.
I first noticed the problem, when I plugged a baby monitor camera in the upstairs standard outlet. The moment I plugged anything in to that outlet, the GFCI downstairs would trip.
This was the first time that GFCI had tripped since I bought the home 5 years ago. I changed the upstairs outlet, and it worked just fine, when I would plug something in.
"Daddy fixed it! He's obviously a master electrician!!"
Not so much.
Now, when we would run the washing machine prior to this whole charade, there was never any issue. I changed the upstairs outlet, and now (not every time, or at any particular point of a wash cycle) when we use the washing machine, it trips the GFCI outlet (the main, obviously).