Nothing works. Refreshing, different browser nothing. I went through the same thing when redeeming Adler, had to wake up early in the morning and finally got him
It seems, to your point since you said it worked the next morning, that some of this is purely due to some event or marketing pushing a lot of people to that website at the same time. However, you shouldn't have to be finding these "low volume" times to redeem your code. We've been monitoring all of the responses here and will ping the team about it tomorrow to see if they can look into it further.