Update on Post
So Im bring this up again and I hope this gets fixed immediately because now with the unit "Rikudo Stealth Dragon, Gehourakan", players who are not aware of this GC glitch/Error, will unintentionally call their g1 unit to the GC causing this to occur more frequently than usual causing the error to appear in CFA. I believe this will be a huge arising problem due to the support of dominate throughout the next set so I hope to see this being addressed as soon as the next update :)
Thank you
Previous Information regarding this old post
Spoiler
Im sure by now, this has been something that has been seen and may have been addressed before.
When Both players call a card into the Guardian Circle, the opponent's card will be sent to the drop zone as well. This occurrence of the card being placed into the drop zone would continue to happen every time, a player removes the card(in the GC) into the drop zone causing the Guardian Circle to be rendered useless for the rest of the match and in some/most instances, causes the game to crash.
I understand that this can be avoided and does not always happen however, I hope to see this being fixed or addressed in some way in the future.