[NEEDS INPUT] [V] [IL] Vampire and Mermaid Couple Cannot Have a Vampire Baby

I'm sorry to be late to the discussion, but I discovered what happened to the children of vampires and mermaids on May 9th. I hadn't played them since until today.

I had no idea that Sims were speciesist and shouldn't have babies if their partner also has a dark form or a mermaid form -

So my poor broken children have no tails, burn in the sun, and are the progeny of Amalea (mermaid) and Johnny Zest (vampire) after many hours of playing. I have another couple, Aleah (mermaid) & Don Lothario (vampire), who just started having children, and it's likely they will have the same issue.

I was going to use these families to start my legacy family challenges, and now I can't even play them. I found a cheat to keep the kids from burning to death, but I'm still incredibly disappointed right now.

I think this bug happened a year ago when Island Living came out, and then they found a way to fix this bug later on, it may of seem to come back again with this bug, but I do have a vampire and a Mermaid couple married and when they try for a baby. I notice it's always a Mermaid baby. I haven't got any Vampire babies from this married couple yet, but I discovered a issue along with them having a baby. Some how I notice it was a mix between Vampire and Mermaid, and what I did is, when I age them up to a Teen. I had to use the vampire cure to get rid of the Hybrid from it being half vampire and half Mermaid. I had to use the cure to get rid of the vampire form, then it switched to full Mermaid. It seems when I tried to get rid of the Mermaid form first, it wouldn't work so getting rid of the vampire form has to come first in order for it to work right. That is something I had to fix or work around from this bug.

Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? 3/3 (three vampire/mermaid hybrid children for the three offspring of a vampire and mermaid.)
What is your current game version number? 1.63.136.1010
What expansions, game packs, and stuff packs do you have installed? All except Eco Living
Steps: How can we find the bug ourselves? Have a vampire Sim and mermaid Sim try for baby. The resulting children were all broken hybrids with invisible tails who tried to swim through sand and burnt in the sun.
What happens when the bug occurs? The children aged up, and as they went swimming for the first time, they lost their bottom halves after getting out of the water. No tail, no legs. Unable to access the panel for vampires to spend points for powers.
What do you expect to see? I would expect Sims to be either vampire or mermaid, or a functional hybrid with some kind of balance between vampire powers and hydration instead of hygeine.
Have you installed any customization with the game, e.g. Custom Content or Mods? No.
Did this issue appear after a specific patch or change you made to your system? Not that I know of
Please describe the patch or change you made. The most recent patch/Eco Living, but this bug happened months ago.

I cheated the vampire power to keep my Sims's children from burning to death, but I couldn't play them without bottom halves. I ended up following another Simmer's advice, and I gave each a vampire cure and then made them eat two kelp apiece. All offspring are now plain human.