Morgana Black Shield no longer blocks Tahm Kench Devour

Hi there,

I was laning using Morgana top vs a Tahm Kench, and cast black shield on myself when I had the red fish/3rd hit Tahm debuff on me.

I'm fairly certain that before, the Black Shield would prevent Tahm from performing a Devour (w) on the shielded person, but he was able to eat me.

I'm not sure if this is design intent; it really doesn't make sense to me, as otherwise a core piece of Morg's functionality is just useless.

It's possible I'm misunderstanding something, but Morg is my second most played champion, so I don't think so.

Thanks for any clarity.