No one is going to have the answer, but I can make a couple of guesses. Spoiler Guess One: Time is an alien concept to Dormammu. He never experienced it before because his dimension is out of time. Doctor Strange explicitly said he was drawing on the power of his dimension in the Dark Dimension. Kaecilius and the Zealots obviously have experienced time before. Guess Two: This one is more mundane. It looked like people were freed from being frozen in time when they were touched by Strange or Mordo. I'm going from memory, but it looked like someone accidentally brushed against Kaecilius, which started the chain reaction. Actually, Guess Three: Just as a third alternative, it's worth pointing out that freezing time and a time loop aren't inherently the same thing. We don't know if the Zealots could break out of that.