@eugshdjgvog9wej , thank you for replying and thank you for the pictures! (Pics can be a huge help!) 😇
Due to the complexity of your families and gameplay, it is difficult to rule out regular glitches in the game. Mixing Occults can cause some glitches, especially in appearance. But that would be just for the offspring! I have not heard of regular human Sims turning into Aliens for any reason! They are not supposed to do that! 😮😞 So, that makes me suspect that a lot of your problem are due to outdated Mods.
You Mods were probably working fine, but we just had 2 updates to the game in about a month, so a lot has changed in the game, and your Mods might be conflicting with it! 😞 You really need to get in the habit of keeping track with whoever made your Mods to see if and when they release new versions and replace the old versions with the new ones. It's kind of like changing the oil in your car -- you might get away with not doing it for a while, but eventually it will cause problems! 😞
So while I don't think all of the odd things in your game are due to Mods (since you are mixing supernatural Sim types) I do think the parents of the hybrid babies changing into other types of Sims is probably related to outdated Mods. I have experimented with hybrids a lot in my game and have never had the parents change, but then again, I don't use Mods/CC! 😳 (I don't like having to do all the upkeep!) 😃
To test to see if one of your Mods is causing the problem, please do all steps of the following:
1) Move your Mods folder to your Desktop
2) Delete the localthumbcache.package file in the Game Folder
3) Repair your game in Origin by logging into Origin and to to your Library. Right-click on The Sims 4 and choose the option to "Repair Game". Wait until Origin fixes all of your packs and not just the base game.
4) Now when you turn on your game it will create a new, empty mods folder. Check your game to see if the problem is fixed.
5). You can now add your Mods/CC back one at a time checking the game each time to see which one is the culprit. If you have a lot of Mods/CC then you might have to do the 50/50 Method.
6) When you find the culprit(s) you will have to go to the creator's site and get updated versions of these (as soon as they update them) that work with the patched game. You will have to use the new version in place of the broken ones.
It is the responsibility of the Mod/CC creators to update their items when EA updates the game. It is the responsibility of people who use Mods/CC to make sure the Mods/CC they use are up to date! 🤨Mods/CC do require regular upkeep! 😞
Anytime EA releases a patch/update, and your game starts acting strangely soon after that, it is always necessary to do the above steps to determine if the problem is Mods related or if it might be a bug that everyone is experiencing. If a mod is the problem then just get the new version. If a mod isn't the problem, then you can always check the Bug Report section to see if a Bug Report has been filled out on same subject, and if it hasn't , you can fill out a new Bug Report ! 😉
Also,since it seems like you have been playing that family and save game for a long time, there is more chance it can become corrupt. And deleting the localthumbcache.package file (after moving your Mods folder to your desktop) and then fixing your game in Origin should help with that.
Please update us on how this works our for you ! 😇 Best of luck and Happy Simming! 🥳