Frogspawn can be picky. While I've never seen them do that, they can be off an on. Mine has been refusing to open all the way since I moved to a new tank a month ago (only coral not totally opening), but after I read what Alton posted I moved my koralia just a bit to direct flow over it instead of into it and it seems to be responding well after only a few hours. It is also worth mentioning I moved it to a spot where it got better light a few days ago, it was kind of between fixtures so it was only getting spill instead of direct light.

Glad your guy is doing better.