Question Gridboss + Flexboss21 Battery Charging Stopped during grid dropout (excessive solar available)

We had a nearly perfect sunny day.  Around 3pm we have the grid drop out for about 5 minutes. I was in self-consumption mode with batteries charging and more than enough solar to run the house and charge the batteries.

Battery bank was as 89% charge (46kWH of batteries).  SOC balance nearly perfect, but not an issue as full charging resumed shortly after grid-restore. 

• Solar was producing 7.8KW of power. 
• My house was consuming ~1.35kW 
• Net:  Battery charging at ~6.4kW

At the exact time the grid dropped, the sum of all 3 MPPT dropped to 1.3kW matching the load.  Battery charging stopped.   

Why would this happened and any specific settings I need to look at?  I do not run off-grid mode (i just do 0 export and fast 

I have the following set:

• Power Backup = Enabled
• Seamless EPS switching = Enabled
• Grid Sell Back = Disabled
• Fast Zero Export = Enabled

The house did not appear to glitch or anything (we were not home, sensitive items did not restart). I'm confident the EPS functionality worked fine going in and out of the grid. House voltage appeared stable, etc.  

For all practical purpose, I was essentially off-grid during the outage but the Gridboss/Flexboss21 decided to react to it.

Gridboss Firmware = IAAB-1600

Flexboss21 Firmware = fAAB-2727

Note:  The first blip is a cloud.  Full sun returns and then the power drops.  Charging continues 45s or so but I suspect that is the resolution of data going from Solar Assistant into my Home Assistant app.  Charging resumes after the grid is restored.  I suspect this is a 300s timeout between changing modes.  It is possible charging would have resumed on its own but I cannot tell since the grid was restored around the same time.

Any recommendations on how to decouple battery charging from grid status during excess solar production?

Thanks,

Tim