Picking rule with specific customer did not work

In EBS 12.2.7, we have a picking rule defined with Shelf Life Days = 152 and assigned it to a few items. We want to ship one of those items with minimum of 60 shelf life days to a specific customer. We assigned an existing picking rule with Shelf Life Days = 60 to the specific item with the appropriate customer name. The sequence number is higher than other items with same rule (60 days) and lower than the original rule (152 days) with same item and no customer name. The rules were regenerated. However,