CTRL - "flipping" inconsistent

[Trundel]

I've built a plugin that requires dealing cards facedown to the table. The CTRL key works fine for awhile but then it becomes unreliable. It will say "flipping" in blue but the card ends up face up. If I grab 5 cards sometimes 4 will remain face up and one face down. Things seem to work ok at the beginning and get to the point where it doesn't work at all.

I'd use the game zones but I have 9 to represent the "box" and I'd need another 6 for "locations" to not use the table for this purpose.