Same happened to me on my 3-phase setup when one of the CT clamps on the Victron Grid metering unit(VM-3P75CT to be exact) got unlocked causing the ESS to discharge wrong amounts to said phase where the CT was fully open. Took me a while to figure out why the resulting vectors on all phases did not add up to 0(no importing or exporting). After it happened the 2nd time after MAKING SURE the clip was connected properly, I taped the CT with electric tape for couple of rotations. Hasn’t happened since.