Ptolemy's entire attested career was at Alexandria, where he made his astronomical observations, but no ancient source records where he was born; a medieval Arabic tradition names Ptolemais Hermiou in Upper Egypt, unsupported by any earlier source and generally doubted by modern historians of science.
What would resolve this A Hellenistic or early Roman record naming his birthplace directly, independent of the later Arabic tradition.
OpenHistory of ancient astronomy; classical scholarshipNicholas Campion, A History of Western Astrology