I have 2 x 5kW Deye inverters (master and slave) - 12 panels (2 x strings of 6) hooked up to the master / 6 panels (1 x string of 6) hooked up to the slave. Slave panels get morning sun and master panels get afternoon sun. Master's panels generation capacity is limited to the slave's panels capacity, i.e. if the 6 slave panels generate 2kWh then the 12 master panels generate up to 4 kWh, but in the afternoon when the sun moves away from the slave panels and shines squarely on the master panels, the master panels generate a lot less than what they should (e.g. if the slave is only generating 1kWh then the master panels - in full sun - only generated 2kWh between the 12).
Once the initial drop in generation on the slave panels (when the sun has reached its peak and starts moving into the afternoon space) occur the slave starts pulling power from the grid and continues doing so until the batteries are at 100% and then still sometimes continues. The battery settings is nowhere near 100% for that time of day and I even went as far as to remove 'charge from grid' completely but still it continues to pull power from the grid.
When I switch the slave's panels off then the master panels start generating normally, but the amount pulled from the grid exponentially increases on the slave.
I'm thinking it's a faulty inverter but would like to know if anyone has any ideas?