Hi,
It is not necessary to restart the server machine, but if possible you can restart it to insure all of the actions have been completed successfully .
You can open process monitor and add a filter "Path is 'C:\Windows\System32\inetsrv\config\redirection.config''', then reproduce this issue. There should be some failure events. The detail description of the event and process contains the user information which can help us pinpoint the source of this issue.