Quattro 12/5000 ground relay not opening fully

Just did a new install on a small vessel and having an issue with the ground relay not opening fully.
When selected on the relay reads 0 ohms as it should, and when it’s deselected it reads between 350-480 ohms of resistance causing my elci to trip.
Has anyone else came across this issue before? If so what was the remedy?

I would recheck this with ALL of the AC wiring disconnected from the Quattro to determine any external leakage paths.
If the N/E voltage is <1V, (it should be much less than that) 350 ohms should give only 2-3 mA of leakage, so should not trip a 30mA RCCB.