Elemental Confluxes

[ProMeTheus112]

I'm playing my map with Heroes V standard (no expansions). When heroes reach an elemental conflux, sometimes they are unable to buy the elementals that dwell in there (the "buy" button is grey). Of course, they have enough gold and also have room in their army. Does someone know where this problem comes from, and how to solve it ?

(it seems I can buy the elementals when I'm a certain faction but not with another faction)

[ProMeTheus112]

Well I just found the origin of the problem : they were set to "belongs to player 2". It's kind of stupid because it doesn't show in game at all, but in the editor you can have Elemental Confluxes set to belong to one player, and then only this player will be able to recruit Elementals from them.