If I understand you right, I think the difference in the readings is because of the losses in the cable between the inverter and Meter.
I'm having (somewhat) the same type of discrepancy. But the main difference for me is the inverters feed into my main electrical panel (after some cut-offs). The electric company net meter is on the other side that also feeds to the same main electrical panel. The electric company is reporting my consumption, generation and difference (net.)
The inverters and the electric company net meter is not consistent nor does it seem to be off by a specific %.
Example: (it's been very cloudy and rainy these last couple of days and I do not have older data)
Inverters reporting:
Jan 15th:9.97 kWh total generated
Jan 16th: 2.73 kWh total generated.
Electric company net meter reporting:
Jan 15th:8.53 kWh - Difference of 1.44kWh
Jan 16th: 0.42 kWh - Difference of 2.31kWh
(also showing me the totals for consumption, Generated and net)
Would the house be utilizing the power without the net meter seeing it? and/or the Inverters ->shut offs ->panel ->wiring -> net meter connections be losing the difference? (or the combo) (which that is too much too lose in just connections)
Essentially can I trust what both the inverters are saying they are generating AND what the electric company net meter is reporting?
I used to be an aircraft electrician for many years. But since I've never dealt with this type of issue, I'm hoping someone can verify my list of possible causes or make a suggestion: (house using some, net meter not seeing it) and/or (power loss between all the gear ) or this type of difference is normal? or suggestions to check?
Thank you!