In my survival world i was playing until i killed a pillager captine and got to a village to start a raid then when a ravager came i started fighting with him and notice that some of his attacks don't even damage me and that made killing him much easier

So after that i got into my flat world and spawned a ravager and then tried to kill him with stone, iron sword, with no armor and still can kill him very easily

There is a video in slow motion that shows the ravager attack not dealing damage