I have noticed a problem with TurnItIn settings. In the "Optional Settings", I have always set "resubmissions are allowed until due date," but recently I have noticed that the setting automatically changes to "do not allow resubmissions". Another instructor at my college has noticed this too. Unfortunately, I usually only find out when students complain that there is not way for the them to resubmit, so I end up having to save the first copy of the TurnItIn report and then delete the first submission from the "Assignment Inbox". This happened last night using safari and when I logged in remotely to my virtual machine and checked the settings with google chrome, the auto change to "do not allow resubmissions" did not happen. I didn't want to risk anymore students having problems so I still deleted all of the original submissions and couldn't test if it might have been a safari/chrome issue.
So, I am posting this here in case others have had this issue and know how to avoid it.
Attached is the screenshot of the the settings page when the field automatically changes to "do not allow resubmissions."