I found this tradition concerning the authorship of Isaiah in the Babylonian Talmud (Bava Batra, trans: The William Davidson Talmud). Apparently, they thought that Isaiah’s works were compiled by Hezekiah.
Jeremiah wrote his own book, and the book of Kings, and Lamentations. Hezekiah and his colleagues wrote the following, and a mnemonic to remember which books they wrote is yod, mem, shin, kuf: Isaiah [Yeshaya], Proverbs [Mishlei], Song of Songs [Shir HaShirim], and Ecclesiastes [Kohelet]. The members of the Great Assembly wrote the following, and a mnemonic to remember these books is kuf, nun, dalet, gimmel: Ezekiel [Yeḥezkel ], and the Twelve Prophets [Sheneim Asar], Daniel [Daniel ], and the Scroll of Esther [Megillat Ester]. Ezra wrote his own book and the genealogy of the book of Chronicles until his period.https://www.sefaria.org/Bava_Batra.15a.2?lang=bi&with=all&lang2=en