@dansz
This is not an official ask victron forum.
That being said.
From what it looks like, the inverters are switching between inverterting and connecting or synchronization to poor qnd unstable grid voltages.
You can see the switches also in the frequency changes as you move between off grid and on grid with throttling using frequency and modbus.
Of course your console is real time but the vrm has log distance of 60seconds? If the data points are such that every time it reports its at that level, then the graph will be different to realtime.