Twitch Drops have not been delivered

The rewards linked to my Twitch Drops on the Twitch streaming platform have not been delivered to my game account. Could you please help me resolve this issue?

Make sure that you have viewed your Twitch rewards on the POE website while logged into your Path of Exile account.

This is somehow often necessary for your Twitch drops to actually show up in game, as an additional step after claiming them on the Twitch drops inventory.