Can confirm it hasn't got anything to do with mods. Here is a few screenshots, before impregnation, the new child, and the mod page to confirm. So unless the mods merely being in the strive conquest mod folder archive is causing it, it's not got anything to do with them. The screenshots are in reverse order, but you should see what they entail. 
Viewing post in Slave children still bugged in 10.0a
This may tie in to my observation about having children as well. While granted, in your examples, they are a boy in one and a girl in another, but that may be the difference in parents or possibly your gender slider. I also noticed they were both shy personality, just like all of mine were when I was experimenting. I don't know if that's tied together or not, but it could be worth looking into.
None of my children have ever been male, just wanted to clarify that. I'm assuming you meant in your experience it occurred, but yeah. I've never had a gender swap before. I'm very much a "All de wamen R for me" kinda gamer. I dislike ntr of any kind, even if they're my own progeny. Lmao. So if I ever had a son in the game even with no male slider, I'd have immediately used them as fodder. I generally don't have children, and don't plan to until the end of the game once I'm done. The only reason I had them for this example was because I wanted to confirm if the spirit system was still affecting the results of them. More a bug test than a child interest. Lmao.