As the name suggests delayed activities occurs when an activity is completed after its due time has passed. Delayed activities are identified with a red line on the left side of the delayed activity.
How to revert a delayed activity
1. Click on the delayed task and go into the activity details page.
2. As you can see under the activity name you can see delayed label just o confirm that the task is delayed. Now click on Activity Delayed to change the delayed status of the activity. A drop down will open with two options 'Yes' and 'No'. Click 'No' if you believe the activity is not delayed.
3. Now scroll down till the bottom of the page and click 'Save' to confirm all the changes.