Similarity Reports Explained
If a student's similarity report is still generating, you will notice a 'pending clock' alongside that student's submission as well as within SpeedGrader. This clock will disappear once the similarity report has fully generated.
If you're having trouble opening Turnitin Feedback Studio, check your pop-up blocker settings and create an exception. Alternatively, if a similarity percentage is not yet available, your report may not have generated.