Single multiplus 15000 in 3 Phase Ess repeated spikes in grid usage on single phase

[Cpt_Echo]

Hi all,

Hopefully someone is able to help or at least have an idea what the problem is here.

I have a single multiplus ii 15000 on Phase A in a 3 phase grid feed.
Multiphase regulation is on and 95% of the time it works perfectly and phase A back feeds to balance out Phase B&C to within the normal ±50 watt fluctuations as it tracks grid setpoint to 0

However periodically (some times once every 20 minutes or so, sometimes once every few hours) the multiplus will completely stop offsetting any usage at all for 2-3 minutes before returning to normal regulation.

There are no errors, no overloads, no voltage sag, no frequency shift etc detectable that would sometimes lead to this scenario that i can see.

Grid meter is EM540, and there is no communication issues with it (i can see the values updating multiple times a second during these spikes live & if it wasnt i wouldnt expect to see all the values logged in VRM, it would have a gap in the data, not spikes on a single phase)

I have a bunch of screenshots from VRM from last night when it happened 3 times in an hour which hopefully help illustrate the problem

[Cpt_Echo]

Unfortunately still experiencing this problem,

I have setup a simple node red dashboard that tracks what setpoint the mutliplus is being instructed to follow by ESS, and what ac output power it is providing, and can clearly see that the multiplus intermitently just stops trying to track the setpoint and drops to near 0 inverter output.

Any insights or ideas on this would be greatly appreciated