According to the Job translation by Greenstein (2019), Job 4:12-21 should be located following Job 3:26. He explains:

“For many reasons the passage 4:12-21 should be read here, right after chapter 3, as the conclusion of Jobs opening speech. One may suppose that two pages of ancient papyrus or parchment containing the two equal halves of chapter 4 were accidentally interchanged in the course of the text’s transmission. In an oft-compared Babylonian composition about a pious sufferer (“I Shall Praise the Lord of Wisdom”) it is the complainant, not the would-be sage, who experiences a divine revelation. It is also Job the sufferer, not his companions, who receives a theophany near the end of the book. More important, in the ensuing chapters both Eliphaz and Job refer to Jobs claim to have enjoyed a revelation. Further, Eliphaz (in chapter 15) and Bildad (in chapter 25) cite the words of the revelation as Jobs, and Elihu, who engages only with the arguments of Job, quotes from it (33:15).”