I couldn’t find any verified answer to this question. Wondering if anyone has one? I’ll post what I found here.
There seems to be no difference between “habibi” and “habibti,” though the word “(habibi)” is typically used by males at around 18 years of age, while “(habibti)” is used more often by females above that age. It would appear that it’s a pronoun change, then, so as you might use a different pronoun with someone who was younger than yourself, or were both male but the other person older and considered senior to you.