Mermaid/Vampire hybrid problem

I had the same problem. I found that the vamp/mermaids hybrid with tails are very glitchy. I delete them. However, I have 2 hybrids in my game who have the mermaid powers/socials and vampire powers but do not have a tail. They lack the vampire powers tree but have hydration, vampire energy, and thirst on needs bar. I had to cheat to get sun proof, command powers etc. Google Sims 4 Vampire Cheats for the website. Its awesome.
I also cheated last night and gave one of them the witch occult trait. She was originally born between a mermaid and vampire couple naturally in game. However she's become my guinea pig. She has mermaid powers, some vampire powers and needs like thirst and energy. Her spellcaster power tree is there and functioning. I was so excited. I plan on experimenting with her to see if glitches happen. I can post pics tonite after work!