Have a normal diamond sword without enchantments, but I still need around 5 strokes for z. B. A Creeper. What can this be? I play the java edition without mods.
Since version 1.9 you are not allowed to hit one after the other fast, take a break between hits every second.
You must always wait for the bar to be fully loaded again (if you are playing a current version)
Since the mob has a "shield" after a blow from you first, you can do it without causing any damage, so as Butter Cookie has already said, just wait 1-2 seconds between them.