A small residue of electrons needed to charge-neutralize the Universe remained along with free streaming neutrinos: an important aspect of this epoch is the neutrino decoupling. The Big Bang nucleosynthesis epoch follows, overlapping with the photon epoch.
The universe retained a tiny amount of electrically charged particles to neutralize its overall charge, alongside unconfined neutrinos: a significant feature of this phase is the separation of neutrinos. Following this, the Big Bang nucleosynthesis period overlaps with the photon period.