You probably already knew this, but in case you didn’t, in The Books of the Bible (the edition you recommend using with your study guides), the book of Ezra has two beginnings, with the first beginning truncated in the middle of Cyrus’s decree (pages 1401-1402).
This apparent “double beginning” is actually caused by the repetition of the Edict of Cyrus at the end of Chronicles and the beginning of Ezra. This is how ancient scribes showed that the parts of a book that was too long to be contained on a single scroll belonged together: They would copy some of the material from the start of the second scroll onto the end of the first scroll, to “stitch” them together.
In our English Bibles we see this only where Chronicles-Ezra-Nehemiah, originally one long work, has been broken up between Chronicles and Ezra-Nehemiah. But in various manuscripts of the Septuagint (an ancient Greek translation of the Bible), there is similar “stitching” between 1 and 2 Samuel, 2 Samuel and 1 Kings, 1 and 2 Kings, and 1 and 2 Chronicles.
Because Chronicles-Ezra-Nehemiah is presented as one continuous work in The Books of the Bible, and because it’s formatted according to its natural literary divisions, the Edict of Cyrus, in abbreviated and then full form, appears twice at the start of a major division that coincides with the place where scribes originally divided this long work into Chronicles and Ezra-Nehemiah.
This repetition of material created a very interesting question for us on our project team as we were developing The Books of the Bible. It’s virtually certain that Chronicles-Ezra-Nehemiah, as originally written, didn’t contain the abbreviated material at the end of Chronicles. This was added by scribes who put the book on scrolls. So should this duplicated material be eliminated? Or should we now consider it to be divinely inspired Scripture, something that God wants to be part of the Bible? As you can see, we left it in. Our hope was that the duplication (more striking in The Books of the Bible format) would lead people to ask about what was going on, as you just have.
Incidentally, in the latest update to the NIV, the word order has been changed to make the abbreviation at the end of Chronicles less abrupt. In the 1978 and 1984 editions of the NIV, and in the 2005 TNIV, the translation followed the Hebrew word order. The TNIV, for example, said, “Any of his people among you — may the Lord their God be with them, and let them go up.” (Go up where? To do what? Read on . . .) But the latest update to the NIV says, “Any of his people among you may go up, and may the Lord their God be with them.” A better sense of closure, but less obviously abbreviated material that signals a “stitch” between scrolls.