I have the same problem, but every time I load the save file, it gets transferred between my Spellcaster Sims. In one household I've got two and it's random to whom it appears. In another househould I've got four and so far it's appeared to only one of them. I don't know what causes is and how to fix it. I tried to reset the perks and buy different ones, but that didn't help.
It's part of the same problem mentioned here. https://answers.ea.com/t5/Bug-Reports/WORKAROUND-ROM-Spellcaster-Level-Reset-for-Sims-with-Ancient/m-p/8188878#M103714 Once the bar breaks what you experiencing will happen. They found the issue once it's patched your problem should go away as well. Unfortunately once it happens its broken so you will have to use a previous save. A Tip in the meantime that works for me is making sure not to have the magic tab, spell book or anything to do with magic open while actively level your magic. Keep them closed till you see the points appear then stop all training and choose your spell traits then close your spell book etc before training again.
