Ezra's family line in 7:1-5 isn't the same as the priests' line in 1 Chronicles 6. Why?

The Bible doesn't say, and these notes set the two lists side by side without explaining them. Ezra 7 goes back from Ezra with "the son of"; 1 Chronicles 6 goes forward from Aaron with "became the father of" (1 Chronicles 6:4-14). Read from Aaron down, Ezra's list names Aaron, Eleazar, Phinehas, Abishua, Bukki, Uzzi, Zerahiah, Meraioth (7:3-5), and 1 Chronicles 6:3-6 has the same names in the same order. Then Ezra has Azariah, Amariah, Ahitub, Zadok, Shallum, Hilkiah, Azariah, Seraiah (7:1-3). After Meraioth, 1 Chronicles has Amariah, Ahitub, Zadok, Ahimaaz, Azariah, Johanan, Azariah (1 Chronicles 6:7-10), and then Amariah, Ahitub, Zadok, Shallum, Hilkiah, Azariah, Seraiah (1 Chronicles 6:11-14), the same names in the same order as Ezra's from Amariah to Seraiah. A second list in 1 Chronicles, "These are the sons of Aaron" (1 Chronicles 6:50), runs from Eleazar to "Zadok his son, and Ahimaaz his son" (1 Chronicles 6:53), with the same names as 6:4-8. 1 Chronicles 6's line goes on past Seraiah: "Seraiah became the father of Jehozadak" (1 Chronicles 6:14), and "Jehozadak went into captivity" (1 Chronicles 6:15). Ezra 7 begins, "Ezra the son of Seraiah" (7:1). Neither book says whether its Seraiah is the other's, or the "Seraiah the chief priest" of 2 Kings 25:18, and neither says why its list is written as it is. These notes don't say which names in one list stand for which in the other, or that any name was left out or counted twice.