I'll let Jared go into detail on what's going on with his anemones but H. Magnifica and S. Gigantea are the hardest anemones to keep alive, so if you have deflation or a gaping mouth present from either species treatment is almost always a critical step that needs to be taken with them.
Also anemones, especially H. Magnifica and S. Gigantea as these love high lighting, do not bleach like corals. They usually bleach when they do not get enough light as light is their main source of Zooanthellae production.
Well said justin.