"Probably an undescribed species.
This is indeed quite similar to Glossodoris symmetrica (note this is the correct spelling of the name, not “symmetricus’), but Glossodoris symmetrica has a narrower red submarginal band and opaque white markings on the mantle like Glossodoris pallida.
It is also similar to Glossodoris electra, but that has a bright yellow marginal band and brown rhinophores and gills."