Sword issues. Can only swing once every 5 seconds.

When ever I swing my sword it BARLEY does it. I can spam click it and it only swings once every 5 seconds. This has been going on for the past year. I didn't think it was a bug for a while because of the update, but now I see others swinging there sword and it works with every click.
I've tried multiple versions of Minecraft on both lap-tops.
Edit It dose not do it in single player, It works normally. But in multi it does it.