Working on a new construction Basement bathroom install. I ran a dedicated feed to a GFCI outlet then out the Load terminals to a secondary plug and the light and fan switches (the fan is in the shower stall and must be GFCI protected). When I turn the fan off, it will sometimes trip the GFCI. I was thinking the spinning fan motor was generating EMF, so I tried a double pole, single throw switch to break both the positive and negative wires at the same time. Still tripping the GFCI. Tried running a second wire from the line side of the GFCI to the fan. Still tripping the GFCI when I shut off the fan even though it should be bypassing the GFCI. What is going on?