I'm using Spigot 1.12.2 and my achievements are showing in chat. I typed "/gamerule announceAdvancements false" in game and it said it's updated to false but it still shows up for some reason. And 1.12 doesn't have the option in the server.properties to disable them.
Weird, that command should've worked. Also, it's not going to be in servers.properties file. It doesn't exist in 1.12. An alternative way is to go in spigot.yml and find stats: disable-saving Make sure that is set to true and it should disable advancements. Hope that helped!
