I have had a strange bug several times now where 1 tool begins to function like a different tool - for example a pickaxe begins to function as a rake. The tool makes the different tool sound - for example hitting stone with a pickaxe makes the sound that a rake should make hitting stone, not the pick axe sound. The function is also swapped, the material actually increases in size as if I am right click raking it, rather than getting destroyed by the pick axe. I have had the same issue with a sythe as well.
Leaving and re-entering a server does not fix the issue, but closing and re-opening the game does fix it.
Sorry I don't have any better details to give!