Toadstools are super hardy corals. I have had mine go weeks without any polyps emerging.
Like Robb mentioned, toadstools go through shedding phases, though normally the the polyps are nott out at that point, and they get very shiny looking.
I would suggest possibly moving it in the tank. It might be looking for more water flow or light.
In terms of feeding, they mainly feed on light. I have never really seen the tentacles grabs anything, though I do add phytoplankton and other like food in the tank.