Aurelion Sol Manaflow Band [GAMEPLAY]

In patch 9.11, Aurelion Sol's passive (along with his W) would proc the rune "Manaflow Band". It seems in patch 9.12 this is not the case. I have included a streamable clip of me procing my passive on the enemy champion several times and not activating the rune "Manaflow Band" until I land Aurelion Sol's Q on the enemy. Simply lock in the champion "Aurelion Sol" take the rune "Manaflow Band" in the sorcery tree and use your passive or W (passive expansion) to attempt to activate manaflow band. This happened for the whole duration that manaflow band was pre 250 stacks. I never proc'd manaflow band through Aurelion Sol's passive.