Thanks to mis on Discord for reporting this bug and being patient while we rooted out the cause! This update brings a temporary workaround to a bug, where discounts aren't applied to some/all trades on some servers. You may not have this problem, but if you do, see the new "TradeDelay" option in config.yml.

This issue was likely caused by a race condition inside the Spigot API's implementation of the new MerchantRecipe#setSpecialPrice method. It seems the order in which the special price is applied to the recipe (before or after opening the trading window) depends on the server's hardware or software. I will work on a proper fix in the next update.

I also added another new config option in config.yml to allow multiple players to trade with the same villager at the same time.