When a Multi / Quattro rejects the grid because it is non-compliant, VRM/Venus OS report a Grid Loss.
Strictly speaking, the grid is still there, but it is being rejected by the inverter. As my clients would say, "The oven still works, why doesn't your inverter?!".
I suggest this be distinguished from a Grid Lost alarm and be reported as Grid Rejected.
This allows us to better support our clients by reporting the issue to the utility for rectification. It also helps us to explain to our clients why their essentials loads are running on backup while the non-essentials are using the grid.
This is especially with the MultiPlus-II platform which is more picky about what power quality is considered acceptable given the various local grid codes it implements eg. NRS-097 in South Africa.