Playing Assassin's Creed Origins, I noticed in Faiyum town criers declaring the segregation of the Greek ruling class and the poor Egyptians, who were to be confined to slums. Beyond the typical divide between the wealthy and poor, was there official ethnic segregation at any time under the Ptolemaic dynasty?
NOOOOO!
This was only thing that bugged me more than the portrayal of Cleopatra. AC:O is amazing but the game's portrayal of social divides in Ptolemaic Egypt along ethnic and racial lines is inaccurate in many ways. For one thing ethnic segregation was never enforced in Egypt because it would just be impossible and impractical, even if we ignore the ways in which divides between Egyptians and Hellenes were cultural rather than ethnic.
I do not have time to type out a full length answer to this but fortunately I have already written a lot of answers to similar questions which you may enjoy:
Did the Ptolemaic dynasty try to Hellenise or segregate Egypt?
What was a typical day in a Ptolemaic-era Egyptian village? (focuses on a village in the Faiyum specifically)
How would an Egyptian in Alexandria at the turn of the millennium have perceived race and skin tone?
Was discrimination based on skin tone present in Ptolemaic Egypt?