Material stacks do not give gold if vendored

Hello,

now i have 3 stacks of materials that do not give any coin if i try to vendor them. First it was a stack of Leather and today a stack of Garnets and a stack of Olive Oil.The material stacks only say "Sell Price: Coin" instead of "Sell Price: 100 Coin".
Now i have the 4th stack, a second Leather stack that does not produce coin if vendored

edit: I observed it closely at all my Civs and i figured out it affects most of my uncommon, rare and epic productions. It also effects common materials, in my celt civ i have animal hides and grain that says "Sell Price: Coin" instead of "Sell Price: 100 coin" and at my greek civ it is copper which behaves the same.
Its very hard to determine why some material productions are infected while others work well.


Hours later: I found a work-around, i rebuild all affected production buildings, i assimilated the affected stacks after splitting them with proper materials(order is important: place materials that have gold value to those who dont have gold value and they will recover gold value)