The system is made up of dual Multiplus II units in split phase (180 degrees), wired to a Victron Autotransformer (for inverter output balancing).
When connected to grid, in this case 50 amp split phase, L1 is displayed at zero or slightly negative on both input and output. L2 is displayed correctly. When inverting both L1 and L2 are displayed correctly on the output.
In previous systems using the regular Multiplus or Quattro, this issue has not been present.
Screen shots below taken moments apart. Same load throughout.