The lost gps signal reason "App not opened after auto clock in" will appear for iPhone users if the time card was auto clocked in and the user did not open the app shortly after. iPhones have a restriction that limits location tracking to only run for a short period of time in the background if the location tracking is triggered by an automatic event, such as auto clock in, and the user does not open the application.

If you have the auto clock in rule enabled for your workforce, a push notification is delivered at the time of auto clock in to remind the user to open up the app. Once the app is opened, the location tracking will be able to continuously run in the background.