From Version 38 release notes
Rare Titan Rewards are reduced if you were not a member of the Alliance at the time the Titan appeared, or if it has been less than 12 days since you received a full Rare Titan reward in a different Alliance. Previously, you needed to be a member of the Alliance 24 hours before the Rare Titan appeared
Any chanche that in the last 12 days you received a full rare loot in another alliance?