Turnitin have informed us that the service is currently experiencing an unexpected degradation. During this time, you may find that Similarity Reports are slow to generate. Students can submit as normal, although we have seen that previews of submissions can take longer than usual to appear. The root cause has been identified and a fix has been implemented. Turnitin are continuing to monitor the situation and will provide an update as soon as the Similarity Report generation times have returned to normal.
Apologies for any inconvenience this may cause.
More information can be found on the Turnitin Status page