Is there a way to make an r15 character to not play ANY animations (even custom ones)?

I'm not to sure if this would fix the problem, but I would try doing this. SERVER SCRIPT

game.Players.PlayerAdded:Connect(function(plr) -- This function fires when a player is added to the game and the plr is the player that joined.
plr.CharacterAdded:Connect(function(character) -- this function fires when the character is added to the game. character is the character that is being added.
local animator = character.Animate -- This line goes into the character and gets the Animate local script, which has all the animations inside of it.
for i, v in pairs(animator:GetDescendants()) do --This line will loop through everything within the animator, meaning it will also loop through the children of the children in the animator.
if v:IsA("Animation") then -- This checks if v (which is the current object that the loop is on) is a Animation.
v.AnimationId = "rbxassetid://1" -- I can never remember if the D is capital or not. If v is an animation, it will change the animationId to 1 so it wont play any animations, since 1 is deleted or does not exist.
end -- end of our if statement
end -- end of our loop
end) -- end of our CharacterAdded function
end) -- end of our PlayerAdded function.

hope this helps!