The ricordea mushroom is capable of movement in two ways. The most common is to simply let go and float to a new spot. The second is to "walk" much like an anemone. This however is very slow and doesn't happen often. If it is inflated but not reaching upwards, it may be fine where it is.
As a side note, ricordeas, like all mushroom corals, are not actually corals. They are members of a group called corallimorphs. Essentially, they are somewhere between coral and anemone.
Someone stop me! Please! But... not just yet...
55 Gal Tropical FW
55 Gal Mixed Reef