Had the same
Also as skipper on flight back to pisa, only about 1.30 and we had an imbalance of over 250 kg less in no2. Balanced on dep and nothing showing centre. On ground mentioned it to 2 engineers . They frowned, shrugged shoulders, hummed and said they would review it, but had no answers.
I appreciate different engines on fleets burn different but this much? I know it's in limits but my exception to rule in 7 years.
Just wanted to say I couldn't get engineers to answer!