Since when I conquer more land, my unit take 7 turns to recruit them in a turn. Although I did have mods, I don't know if that would be the case. And is it because of my Population? cause every turn it doesn't gain any population. It is Zero every turn I end.
Is it because you are recruiting into an army that is away from a city?
I'm not 100% sure about Rome 2, but previous TW games allowed you to recruit away from cities and included time for that unit to travel from the city it would be created in and merged into the army.
Also - if the building or upgrade to recruit a specific unit is in a different city, travel between the recruiting city and the one you request the unit in will be added, too
Are agents sabotaging you? I have not experienced this problem. I generally recruit non siege units in places that will give me large military bonuses (20%-40%). I also try to always have a general that will add experience to recruiting and a movement bonus. I then rush the units in a forced march to the front lines, add them to my favorite general, and then dismiss the recruiting general. Rinse repeat.
If it is telling you seven turns, you are probably being sabotaged by enemy agents. I play on legendary, and having level 10 agents is a must.
I don't use mods, so it could def be the mod.