Hi @scdeller 
Welcome to the Canvas Community. Yes, this is something that I have to mention to faculty at my own institution regarding the default behavior of Discussion. If you look at the fine print at the far right of the screen near the Discussions grouping, it states Ordered by Recent Activity. That's the default behavior. To place Discussions in the order that you want them to be (be aware that this will affect your students, as well!) you must pin them. Check this online lesson: https://community.canvaslms.com/docs/DOC-13065-4152123560 While that lesson implies this is for the short-term, it doesn't have to be. I know faculty who pin every discussion because (again) this controls their order.
I hope this helps a bit, Steven.
