I've noticed this a lot today while I was fighting nodes in the current PVE vs mindless ones.
The board is being reshuffled even though there are valid moves.
I'm certain it happened in 3* human torch node and the 2* Daken node, running the required character with 3* Magik and Deathlok, but thinking back there were more nodes in which this occurred.
/edit: okay, seems I was gotten by the too long power descriptions. Apparently it's a side effect of Magik shifting to the dark side. Move on, nothing to see here.