I was trying to make some invisibility potions to sell in a sign shop. When I tried to put the potion in the sign it said that I didn't have the potion. I checked several times before I decided to buy one and see if there was a difference. Even though the 2 potions were both exactly the same the potion I bought was able to go into the sign while my potion was unable to. I did /itemdb for both the pots and realized they had 2 different ID's. I don't know if this is a glitch or something else. I spent a long time googling what I did wrong and couldn't find anything. Eventually I resorted to experimenting and couldn't find a solution. Please help me because it is getting a bit frustrating.
-kp_armageddon