Please do below setting to make sure your IIS nor go into sleep mode all the time.

1. Open IIS Manager.
2. Navigate to Application Pool, Select the application pool you are using for Autotrack. Right click and select advance Setting... 
3. 
   
4. In Process Model -- Idle Time-Out (Minutes), change it from 20 by default to 0. set it to 0 to keep it running all time even when its idle.
5. 
6. Keeping app pool running all time will consume server's precious memory. It may become critical especially if application is leaking memory.
   
7. Remember to auto restart the IIS so to make sure it work fresh after restart.
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9. MAKE SURE YOU RESTART THE WHOLE SERVER IF POSSIBLE AFTER THE SETTING.