Lps Coral ID help pls.

[Trex-on]

Hi ID help pls. This hitch hiked along with a colony of zoas. So far the only thing I can think its some sort of retracted plerogyra species.
Lps it likes to retract completely at night. It's about 1" in diameter. Have 2 on this piece of LR.

 

[dbraun15]

fungia--or plate coral.

 

[SC reefer]

Fungia

 

[Trex-on]

Thanks for the help. So is this a connected fungia that will eventually break from its rock ? Had thought it was a form of fungi/ plate when I first noticed it but because it fully retracts and has no skeleton was not sure, is that typical of a young fungia?