I have since found the following information about people that did live over 120 years in the Bible AFTER Moses. There seems to be some explanation for why given here, but I am not with the actual source I found this in. I do not know who is interpreting the comments. Can anyone find more details?
Ahijah, the prophet of Shiloh, instigated Jeroboam's secession and predicted the downfall of his kingdom. The Midrash, basing itself on the fact that, according to 2 Chronicles 9:29, Ahijah is described as extremely aged in Jeroboam's time (1 Kings 14:4), and with no pedigree, identified him with Ahiah, son of Ahitub, the oracle-giving priest at Shiloh in King Saul's time (1 Samuel 14:3). He is accordingly singled out by rabbinical tradition as one of the seven long-lived saints whose successive lives extend over the whole history of mankind; each having transmitted the sacred lore from his predecessor to the one succeeding him, while shielding the generations of his time by means of his piety. These saints are: (1) Adam; (2) Methuselah; (3) Shem (Tanna debe Eliyahu R. xxiv.); (4) Jacob (Gen. R. xciv.); (5) Serah, the daughter of Asher, or, as others have it, Amram, the father of Moses; (6) Ahijah of Shiloh; (7) Elijah the prophet, who lives until the coming of the Messiah (Ab. R. N. version B. xxxviii., Seder 'Olam R. i., and B. B. 121b). For the underlying idea, see Ḥag. 12b, and Yoma, 38b, with reference to Proverbs 10:25, Heb., "The righteous is the foundation of the world," and Proverbs 9:1, "Wisdom hath hewn seven pillars." According to this tradition Ahijah lived over six hundred years, having received his "wisdom" from either Amram, the father of Moses (see Amram), or from Serah, the daughter of Asher (see Serah).
If from Serah, his age was considerably less, since she was supposed to have lived for more than four hundred years, until the days of David (YalḲ., Sam. § 152). The reason why Ahijah was regarded as having attained so unusual an age seems to be that, according to 2 Chronicles 9:29, the history of Solomon's reign was written by him; and that he was supposed to be identical with Ahijah the Levite, who was placed by King David in charge of the treasures of the house of God and of the treasures of the dedicated things (1 Chronicles 26:20; see B. B. 121b, Rashi).