Ideas
Just got this too for the first time. Entering CAS, removing tattoos, saving & leave CAS doesnt work for me.
Its not random tattoos either. They are mostly from the same packs. Fairies, werewolves, Bbsiness & hobbies (always left leg). And medical wearables.
In one household it affects one sim slightly different. The shoes and some body paint practically disappeared. I can add it again but when I go into live mode its like I didnt add them.
In the same household Im able to fully edit another sim and it saves when leaving CAS.
What did work was entering CAS, selecting the bugged sim, selecting an outfit to edit, copy it, remove the original, remove tattoos, edit other things, save & leave CAS. The tattoo is now gone but the other things arent saving yet.
At least I managed to change one outfits underwear and got rid of a tattoo on the stomache. Still working on editing a tattoo on the legs.
Temporary solution that worked for me. Since I can change the opacity of tattoos I select the brightest color of the bugged tattoos and set the opacity to zero. This way the tattoo is barely visible.