My Multiplus ii 12/3000/120 50 2x120 was recently installed into my RV. Everything seems to work fine, passthru, charging, inverting, ect. The problem happens when I turn my solar controller on. It almost instantly trips the gfci in the house on the line it's plugged into when it starts outputting power. I've got the multi ground running to the negative bus bar along with the ground for the lynx distributor and the load side of the shunt. Those all connect to the negative bus bar which is then connected to the RV frame. The case of the multi and the mppt are grounded in a different place on the frame. I've metered everything I can think of and can't seem to find an issue. Anyone have any thoughts? Mppt has been installed for over a year without issues until this point.