As you are using the set up, it is not a normal use case scenario.
ESS current control algorithm was designed with a single-input model in mind because the inverter can only actively synchronise + connect to and use one input at a time
I do hear ehat you are saying.
When the generator is active on AC-in1, the ESS logic throttles the AC PV on AC-in2 to prevent overcharging the batteries — but it fails to account for the fact that on a Quattro, AC-in2 is still a live, separate grid connection where excess PV power could simply be exported.
The software doesn’t treat the two inputs as truly independent, so the grid feed-in capability of the AC PV is suppressed during generator operation.
But again this is a niche / abnormal - less than 30 minute use case. Which can be approached differently with an adjustment in how the maintenance run is implemented.