This was not merely a typo, it was based on differences in the underlying texts. “The MT preserves the 3rd person masculine singular form וַיָּבֹא (vayyavoʾ, “then he went”; cf. ASV, NAB, NIV, NCV, NRSV, NLT), while many medieval MSS (supported by the Syriac and Vulgate) have the 3rd person feminine singular form וַתָּבֹא (vattavoʾ, “then she went”; cf. KJV, NASB, TEV).” W. Hall Harris, ed., The NET Bible Notes, 1st, Accordance electronic ed. (Richardson: Biblical Studies Press, 2005), paragraph 18846. https://accordance.bible/link/read/NET_Notes#18846

Interestingly, though the MT is Masculine, the official translation followed the vulgate and went with Feminine.

Can anyone verify this?

This 14th century manuscript (629) is the earliest manuscript to contain the Comma Johanneum. Did the resources get mixed up, or does 629 actually attest to both of these peculiarities?

Should read, "in any greek manuscripts."

The reason he did not supply the CJ is that the MSS he had purposefully omitted the CJ. The reason he supplied the last verses of Revelation is because he knew it was supposed to be there, but the last leaf of the MSS had fallen off.