Has anyone seen odd behavior when students are using the Canvas app to post in group discussions? I have an instructor who has recently learned that twice he has had students  (three in one instance and one in the other) who were somehow able to post to the "main" discussion area on two different group discussions instead of the respective group areas. Clearly, this causes all sorts of issues with the group conversation itself and with Speedgrader. It doesn't seem to always happen when students use the app to post to the board; but when it does happen, the students were always using the app. The instructor didn't know if the students were using iOS or Android. Any insight or adivce would be appriaciated!