Getting a 504 Gateway Time-out from cypress demo site upon attempting to download the master patient list.

Repro steps:
Navigate to https://cypressdemo.healthit.gov/users/sign_in using a browser and sign in with appropriate credentials.
Select Master Patient List tab.
For Annual Update Bundle radio button, choose 2016 Bundle for the 2017 Reporting Period.
Click on the Download Master Patient List button.

Expected result:
Master patient list download is started.

Actual result:
After about a minute, the site returns a 504 Gateway Time-out error.