Dear @Netrange
We have exhausted all options we could think of. Yesterday we completely removed the existing VE.Bus configuration and rebuilt the whole 3-phase system from scratch using Mk3 USB cable. After that, we re-applied all VEConfigure settings and manually added the ESS assistants with the original parameters.
Unfortunately, the behaviour is still exactly the same — nothing has changed. L2 and L3 do not export/invert under ESS control, even though the 3-phase setup and AC measurements are correct.
While checking through the forum, I found two or three other recent threads describing very similar symptoms when the inverter goes into pass-through.
This might indicate that the issue could be related to the latest 3.66 firmware, but I cannot confirm it. At this point, all hardware, wiring and measurements seem correct, and only the ESS logic is refusing to activate discharge on L2/L3. If needed, I can provide full logs (VRM diagnostics, gx-device logs, VE.Bus status, Modbus register snapshots, etc.).
Thank you in advance for any additional suggestions on what else we could try.