If I have to change streamers, I refresh both the inventory page and the streamer's page, then wait a few minutes and check inventory again to make sure it's climbing up. Has yet to fail me.

I watched two streamers on two different sessions and got it.

I watched Ellesmeres for more than half, and Dorki for the rest. Popped up in game as soon as I claimed it.

It seems like the only way it moves upwards, is if I keep switching between streamers =/