Updating a channel header by using the `/header` slash command requires a refresh to display the updated header. This is a regression; does not reproduce on prev.test and was found in a Selenium test. The system message posts as expected but the header does not update.
Refresh is not required if the channel drop-down menu item or the `Add a channel description` link is used.
1. In a channel where you have permission to edit the channel header, use the `/header` slash command to update the header (such as `/header Updated header`)
Observed: System message posts as expected, describing the header update, but the header itself does not update until after a refresh
Expected: Header updates immediately, no refresh required