Nunu snowball crashing bugs?

So I was playing the new nunu today against a Yorick and with a thresh on my team and realized that not only did small Yorick minions stop my snowball which I didn't really understand as they are weaker and smaller than normal minions, my ally thresh ult wall stopped my snowball as well. Is this intentional? It made it really hard to team fight tbh that whole game and ridiculous.