Sometimes it happens that after matching orbs and some cascades of following matches you get two extra swaps instead of one without any card or ability that gives extra swaps. Most likely happens when started with a 5-orb-match. This happens no very often, but remarkably often enough. This was also seen on ai's turn.
It can happen on our turns, as well. There has been a lot of discussion about this over many months now, because it's very random and unpredictable. But, yet, it does happen from time to time. As far as I know, this has never been investigated - and given the difficulty in replicating it, it may be some time before it can be researched, too.
I think the most likely culprit are the permanent supports. It seems like sometimes a match-5 cascade that results in a permanent support color change that also results in another match-5 can sometimes generate an additional extra swap. But even that theory isn't consistently reproducible. I've seen times where that doesn't add a second extra swap.
Truly, a mystery for the ages
Hello guys, Sorry about the delay and thank you for your feedback! This issue is now under analysis.
Thank you for your patience, Marcela.