Not trying to be an apologist, but here is the note in my English Standard Version: "Some manuscripts insert, wholly or in part, waiting for the moving of the water; for an angel of the Lord went down at certain seasons into the pool, and stirred the water: whoever steped in first after the stirring of the water was healed of whatever disease he had." My NASB contains their translation of the text in the body of the gospel, but marks it as probably not in the original writings. The Christian Standard Bible is similarly annotated. My NKJV has the text in question with no comments on it, NIV has the extended version as a footnote.
BTW, biblegateway.com allows you to compare translations on the screen. I think it also has information on the sources for the various translations. And there is usually a display on the bookstore shelf explaining which bibles are most word-for-word and which translated thought-for thought. Interesting information for me, and why I had several different books to check.