I opened a few Grand Tournament packs and the animation appeared to be bugged, the pack didn’t appear until the cards had been dropped, there was no opening animation but there was sound.
I think I have the same bug for “The Grand Tournament” card packs: the opening animation is visually bugged and incomplete (no idea how to better describe it). When the five cards are visible, everything is normal again.
The bug was fixed with the latest patch - thank you 