I've had that twice recently with my Kodak OG5.48 (VMIII) recently but it wasn't random. Both times it happened about 30 minutes after the UTILITY power supply was restored after loadshedding. I didn't wait till the next day to see if the inverter sorts itself out. I tried a few things.
1. Disconnecting and reconnecting PV supply. Didn't work.
2. What did work was to change the inverter from "Solar First" to SBU, which started using the PV again and then switched it back to "Solar First". I assume I essentially just reset some of the firmware's variables which allowed it to operate normally.
I still want to "REBOOT" the inverter sometime. It been running for about 8 months without an interruption of power been fed off it.
Thanks @Coulomb. Interesting note on the voltage. The Kodak OG5.48 (VMIII) has a PV MPPT range of 120V -> 450V. I have 6S x 72cell panels (6 in Series - 6x47Voc = 282V). I know the King is different to the VMIII but I thought they run similar firmware. I'm going to go and do some research. Thanks for always helping the guys.
I've attached some pics. Utility power was restored at about 14:08, PV dropped around 14:38. I noticed it at 16:40 and restored by changing the settings.
From Solaris Assistant:
Firmware version 41.16
Model number 37