Cannot complete ATB Austin Corbett Iconic set but have all the cards

I think it did have to do with the epic Austin Corbett card stuck in a line-up for Arena, but it took two days to resolve. In fact the card didn't "come free: until Unlimited Arena reset at the end of the week. After Arena reset, before I had made registered a new line up to play, I checked to see if the epic Corbett card was available. Nope. I then registered a line-up in 2800 - 3800 and 3700 and above, without the epic Corbett card. Again, the card was not available. Finally, later in the afternoon that day, I played both Unlimited Arena sections. On a whim, I checked to see if the Epic Corbett card was available to complete the set, and it was. Seemed weird, but the issue is resolved now. Thanks for the suggestion. Cheers.