I think this may relate to the differences between the large battery types & the ways the 12v Li-ion battery are being charged by the larger battery in RWD vs LR/P.Interesting that the range change only affects LR. Surely there's a logical reason for it not affecting RWD/SR+? Advertised ranges sandbagged in advance?
The new Ryzen MCU is powered by the new 12v Li-ion battery in all M3 cars, but the 12v battery is being recharged by LFP battery in RWD and by NCA battery in LR/P. Looks like the recharging efficiency for NCA battery had reduced when 12v battery type was changed from lead-acid to Li-ion? While the RWD range wasn't impacted by the same 12v battery update...