This new planet is even fluffier than Saturn. Three times fluffier. Doesn't seem possible.There are at least three possibilities; one is, that the planet is a recent arrival and in the process of spiralling down into the star; a second is, the density estimates are based on screwed up data or interpretation; a third is, the density estimates are wrong because the estimated distance to the system is wrong.
Hoagland cites hyperdimensional physics as the cause of the fluffiness--an input of energy to the interior of the planet causing heating and thermal expansion. This is not one of the commonly accepted explanations.