you didn't block quick enough the animation seems like as if you're blocking but the block itself is not 100% formed
I think there was enough time for it to "form" considering I've blocked attacks a lot quicker than that before lol
you have to take into account your fps, as well as number of players on the server, and if the server is lagging due to strain
that never happens to me as I always block quicker than that lol...
if i did not block as fast i would encounter that but i never have