EPIC 211351816.01 seems to have been re-inflated when its host star evolved into a much more luminous red giant star. This is because when its host star has yet to evolve into a red giant star, the planet is at a large enough distance that the amount of irradiation it received was probably not sufficient to have kept the planet inflated. At that time, the planet would have received only ~200 times the flux Earth gets from the Sun, and that was probably not enough to keep the planet inflated. In a way, the discovery of EPIC 211351816.01 provides evidence that the inflation of a planet is driven by the deposition of energy from the planet’s host star rather than by a slowdown in the planet’s cooling process.
Grunblatt et al. (2016), “EPIC 211351816.01: A (Re-?)Inflated Planet Orbiting a Red Giant Star”, arXiv:1606.05818 [astro-ph.EP]