I have claimed the drops from Twitch 3 days ago (the 8 S1 Lootboxes, to be precise), but didn’t receive anything so far in the game. My Twitch account is connected to the Battle.net, I’ve checked several times.
Always check Bug Report to see the latest known issues. Twitch rewards are likely tied up with this:
There is a maintenance tonight.
Just in case, for how long should I wait before getting concerned? The issue is still unresolved