I just discovered something bonkers and first, thought other people should know about this if they don't already, and second, thought someone might have a solution, so here goes:
I created two discussions, but they were in draft form, so I kept them locked, but I did publish them only because I didn't know if they would show up on the calendar if I didn't. So I went to the app on my phone, just to see if I had any messages, clicked on discussions, and lo and behold, there were my draft discussions for all the class to see! I could even post even though they were locked until August 28. I tried unpublishing to see if that made them disappear, but it didn't.
The upshot: in the app, locked and/or unpublished discussions are neither locked nor unpublished.
Has this happened to anyone else? I don't remember this happening before, and this is the third semester I've used Canvas. It's possible I've just never noticed. Does anyone have a solution? I've deleted the discussions altogether, but I don't like that because then they're gone from the calendar, too.
Very curious to know what others have experienced!