In your simulator configuration with ACSCs (instead of PACK Controllers as in older simulator standards), there are two simulated ACSCs: one for each pack, and each with two independent lanes.
With simulator Std 2.0 and FWC H2-F9D, the alert AIR PACK 1+2 FAULT is triggered (in part) by the internal FWC logic signal ACSC FAULT. The internal signal ACSC FAULT is itself triggered by the signals [ACSC1 FAULT AND ACSC2 FAULT] coming from SDAC. There is no flight phase inhibit in the case of AIR PACK 1+2 FAULT due to ACSC FAULT.
As Airbus noted, when the landing gear is extended, the power supply to all ACSCs is cut, therefore the ACSC FAULT is triggered internally and the AIR PACK 1+2 FAULT is triggered as a result.
Is it possible that the new behavior you noticed is due to the particular simulator software standard which simulates the ACSCs instead of the old Pack Controllers? The FWC logic for Pack Controllers is different, as well as the power supply perhaps.