Glazing bead or glass stop is what they are called. Typically brand dependent as everyone will be different. You can try Blaine Window as they are the go to for this type of product if it is available.

+1. Can you figure out the brand on the window? Open it up and look on the sashes.

There lies another problem, the only label is the NAMI sticker, and the seal between panes is labelled duraseal. Those are the only identifiers on these windows. I'm going to go around locally since the majority of these homes were contracted suburban developments.

Other option would be some sort of universal glazing bead that is rated for exterior use? Thoughts?

Start with Blaine and remove a section from the broken side and see about sending it to them. They will probably be able to match it.

That will be the plan after the holiday, I appreciate y'all's input, very happy with my first post! Thank you