[astrobe_]

It seems this -que was already a relic at that time, or maybe sort of literary, because it coexisted with et (as in etc, et cetera, &c), which still exists e.g. in French. Or maybe one is from antic Latin and the other is from "vulgar"/late Latin ?

[prox]

I think PolyMathy on YouTube went into this topic, and it is part of Greek.

It was probably this video https://www.youtube.com/watch?v=a5CUiP5oiH0

[dhosek]

There were a number of different ways to write and in Latin. The Vulgate Bible, apparently unhappy with all the vav-connectives in its Hebrew sources uses them all.