[Pygmypuff]

How long ago is it since you have put her back in her cage from being out in the pet safe room?

She could have found being in the room stressful - often hamsters are frightened in big open spaces due to their natural prey instinct of wanting to hide for safety and being frightened of predators. If you take her out in the room again, make sure she has plenty of dens and toys, and if possible access to her cage, so she doesn't feel so vunerable.

Otherwise, I'm not sure. Any kind of change can be stressful for hamsters but they usually calm down relatively quickly, once they know they are safe and back in their territory.