Vindicators are not showing when celebrating

So my friend wanted to know what will happen when illagers won a raid, so we did that. i recommended wave 7 because there are more illagers in there so when wave 7 was active, i did the kill command and killed all the villagers and my friend was laughing at the dancing pillager and the evokers, but he stoped laughing and said,"hey, the grey shirt illager doesn't have arms!" and i was like,"what do you mean?" so i went where he was and saw the the vindicators have no arm animation when celebrating!(i notice the problem when i activated the classic texture update pack before 1.16)