Sorry to hear your having issues. Due to the internal charger design on the Renault Zoe they are prone to earth leakage causing RCD tripping issues.
You haven’t mentioned in your post what earthing arrangement you have? Zoe’s require a good earth (<150 ohms) depending on the regulations in your country this should be provided for by a TT-island earth rod i.e don’t connect the EVSE to the supplier earth but use an earth-rod installed by the EVSE instead. You will require an earth loop impedance tester to test the earth, however the Zoe does an earth loop impedance test each time a charging session begins, if a charging starts successfully is safe to assume <150 ohms. I believe you can see the reading of this earth loop impedance test performed by the car by using CanZe bluetooth app tool.
If you have installed the unit using a Type-B RCD then it’s safe to disable the internal GFCI. With the GFCI disabled you should not get the error but your upstream RCD may then trip. The GFCI in the EmonEVSE is more sensitive than the type-B RCD. As a final resort you could remove the GFCI CT inside the EVSE.
Have you tried three-phase charging with your Zoe at other charge point locations? It’s possible that an issue with the car is causing this e.g: https://www.speakev.com/threads/renault-zoe-tripping-multiple-charge-points.33593/