What sources, prior to the 19th century, support or refute the existence of the Council of Jamnia/Yavneh?

Question

Multiple questions on Christianity.SE¹ refer to the Council of Jamnia/Yavneh in reference to the canonization of the Bible (Tanakh). Wikipedia states:

In 1871 Heinrich Graetz, drawing on Mishnaic and Talmudic sources, theorized that there must have been a late 1st century Council of Jamnia which had decided the Jewish canon. This became the prevailing scholarly consensus for much of the 20th century. However, from the 1960s onwards, based on the work of Jack P. Lewis, Sidney Z. Leiman, and others, this view came increasingly into question. In particular, later scholars noted that none of the sources actually mentioned books that had been withdrawn from a canon, and questioned the whole premise that the discussions were about canonicity at all, asserting that they were actually dealing with other concerns entirely.

Jacob Neusner published books in 1987 and 1988 that argued that the notion of a biblical canon was not prominent in second-century Rabbinic Judaism or even later and instead that a "notion of Torah" was expanded to include the Mishnah, Tosefta, Jerusalem Talmud, Babylonian Talmud and midrashim.

Can anyone quote the specific Mishnaic and Talmudic sources here? Are there any additional pre-19th century sources that speak about the Council of Jamnia/Yavneh?

Please note that this question is not asking for arguments supporting or refuting the Council of Jamnia/Yavneh, it is asking for pre-19th century sources.

¹ _{Here, here, here, and here. Two of these do mention that the council may not have occurred, the other two take it as a given that it did.}

Answer 1

According to the Jack P. Lewis' chapter "Jamnia Revisited," contained in the 2002 anthology The Canon Debate (McDonald & Sanders, editors), the theory that the Tanach was fixed by a Council of Jamnia about 90 CE was first proposed by Heinrich Graetz in 1871. W. M. Christie was the first to dispute this popular theory in the July 1925 edition of The Journal of Theological Studies in an article entitled "The Jamnia Period in Jewish History". And the theory began to go into further disfavor following a critique by Lewis in the April 1964 edition of the Journal of Bible and Religion entitled "What Do We Mean by Jabneh?", and other critiques thereafter by Raymond E. Brown and Sid Z. Leiman. Today, Lewis says, the theory is largely discredited.

According to the Babylonian Talmud (Bava Batra 14b-15a) and Rashi's commentary to Talmud tractate Megillah 3a, 14a, much of the contents of the Tanach was compiled by the Men of the Great Assembly (Anshei K'nesset HaGedolah), by about the year 450 BCE, and have remained unchanged since that date.

While Rabbi Akiva, for example, appears to have been involved in the debate to include Song of Songs into the canon (Mishna Yadayim 3:5), I think he was merely defending its inclusion after the fact, and that the post-Temple rabbis did not take part in the canonization of the Tanach. While there are other examples of Tannaim discussing the relative merits of some of the kesuvim, and whether they deserved to be included in Tanach, there does not appear to be any chain of tradition to tell us that the Tannaim (or there predecessors, including the Anshei K'nesset Gedolah) actually conducted anything like what we would call canonization.