WW glitch? idk

Does WW's E act as a spell shield in conjunction with his W? When I use Trist, occasionally i'll be in a position where I have to R him away, but it doesn't do anything. There are no minions or anything around, it's usually me and him and my ult goes on CD, but he takes like zero damage and doesn't get knocked back at all which is odd because sometimes I can knock him back right as he's in motion to do his ult. It's really weird and I reported it as a bug, but I'm not sure if there's something I'm missing nor do I know if Riot will actually answer me back. Curious if anybody else has experienced this or something similar, and what's up. Mind you, this happened in my last game as well where WW had two complete items, an unfinished jungle item and boots. Neither of his completed items allow for a spell shield, and if I have 3 complete items I should do at least SOME damage to him even if it's substantially less due to his E. Though, I doubt a level 12 WW E can negate over 80% of an R from Trist or at least enough where he lives through it even though he has ~150 HP left, and plus there's the no KB thing. It's just really weird to me. lol