Can anyone explain why students are able to submit their Google LTI external tool assignments after the Canvas assignment has been locked? I wanted them to be able to submit their final in a Google Doc so I could use the plagiarism check feature.  I locked my final exam for 3pm, but I still had a student able to submit her work at 3:38pm. I double checked dates and times and everything and nothing is amiss.

Any guesses why an assignment has the feature to be locked if it's not really??