https://media.discordapp.net/attachments/671895772265971712/986079946168492032/Screen_Shot_2022-06-13_at_8.28.49_PM.png?width=1440&height=224

This seems to be an incompatibility with certain mods like MCDC and not with lithium. When running a give command with MCDC and IP the item is successfully given but with the error in the above screenshot and without any output to the log. Additionally when disconnecting and reconnecting the items given with commands are duplicated and dropped to the ground.

Ah you're right, it was an issue with MCDC. Lithium seems to work fine; I guess I removed the both at the same time and assumed it was Lithium's doing, my bad.

Btw Discord4Fabric is a good alternative