While editing an announcement in my course, I encountered the following warning message:

"Students have already submitted to this discussion, so group settings cannot be changed."

I'm curious about how this warning applies to an announcement. What exactly does it mean by "group settings"? Does this imply that announcements cannot be edited if there are existing comments on them? Is not that setting (Allow Participants to Comment) off by default?

Furthermore, the announcement I'm currently editing does not contain any student submissions or comments. In what way does this warning message apply if the Allow Participants to Comment setting is turned off or the Disable comments on announcements is enabled at the course level?

Am I overlooking something here?

Additionally, I noticed that the screenshot in the How do I edit an announcement in a course? article also displays this warning message.

PS: Is this a bug?

Thanks!
P Jalakam