Growatt R&D don't care about poor performance
The MPPT (Maximum Power Point Tracker) in the Growatt doesn't work when there is just a few shadows on the panels - performance drops to 10%. It's a malfunction because the algorithm can't find the correct Power Point. Fronius invertes has a MPPT that actually works with shadows, but Growatt R&D doesn't care - they say that they have more important tasks. Don't buy Growatt if you expect to have shadows on the panels - buy Fronius instead.