When reselling an item to a vendor who has since replenished the item, the resold item(s) forms a new slot in the vendor's inventory, instead of combining with the similar items.
Example: The alchemist in the Gnisis temple has 10 Netch Leather that replenish every day if bought. If you buy the 10 leather, wait 24 hours, and then resell the leather to the vendor, there will be a total of two seperate stacks of leather in the vendor's inventory after the transaction, each with 10 leather. If you buy both stacks again they combine into one slot (20 leather) in your inventory.
#1 Updated by Enrico Seeger about 3 years ago
I've performed additional testing.
Bug occurs independent of mods.
The way I understand it is that everytime an item passes through your inventory it becomes differentiated from any items that haven't. It will still prevent a merchant from replenishing, which is good! If you buy two stacks and sell them back separately they will combine in the merchant's inventory, but if you only buy and resell the same stack X number of tines, the two stacks will never combine.