I'm playing with a fully customized party on my Note 4, and at level 10, when the HP gain is lowered, I'm only getting the class HP/level, not the Con bonus. My druid, for example, gets +2 class and +2 Con (16), but she only nets 2 HP per level. I play on easy, so my rolls are maximum.
Stranger still, I have a sorcerer (dragon disciple) in the party who gains no HP/level.
EDIT: Nevermind, he's getting one per level (class HP) but not getting Con bonus either.
The druid has never been exported or imported, and the sorcerer was imported to the expansion, exported again, and imported to a new non-expansion game.