Equal items are stacked in different piles. Same item, different language, different piles.

Many items are not stacking correctly. They are the same items but duplicated. My server is LATAM so many players use the Spanish language, and there are 2 distinct stacks when looting. 1 stack with names in English and the other stack with names in Spanish. I don't know how to fix it since it's annoying to loot the same item and have it stack in 2 slots both in the inventory and in the containers or warehouses. I need help please. Thank you.