I’ve married a Scottish princess to a Mongolian general

[Boryszkov]

As in title, first I bribed two Mongolian generals, then I sent two princesses to marry them, even though normally it is not allowed to marry between religions, it worked here, the issue is, that for the duration of both of their lives there were no adoption offers, no children and no marriages, when they died the usual Muslim grave appeared and everything turned back to normal. Has anyone ever tried this and was the stagnation a bug caused by unintended use of the family tree?

[isa0005]

When a general joins your faction, he effectivly takes on the religion of your faction. Not being able to marry princesses to other factions of different religions is specific between factions, not between your own generals.

[Boryszkov]

Yeah, so get it, what I mean by culture is that their portraits and other religion specific general segments were still Muslim, and what made me think was literally no additions to the family tree during their lifespan

[Dismounted Feudal Knight]

Seems more likely that you've hit the game's archaic general cap wall (other trees producing more than enough heirs makes the game compensate on other family trees in relation to the amount of territory you have) or there was something wrong with fertility of the general (possibly princess, but most likely general if this is the case). That effect is odd, though; I might need to do a mockup and test it.

[Steward Denethor II]

The issue should not be religion, Catholics can marry Orthodox or Pagans no problem. Princesses can only marry generals from factions that also have princesses however. It is weird that you could do that. Are you using any mods? If you had more regions than generals that could explain it.

Edit: Oh I see you bribed him first. That makes it more odd. Maybe the designers don't approve of intermarriage (lol).