Jot Form Error: 502 Bad Gateway when submitting

One of my submitters is trying to submit an EDIT link of their form, and they keep getting the error in the attachment. Please advise. 

https://www.jotform.com/edit/3877118560528806291

Hello,

It could have been a glitch due to heavy traffic at the time the submission was made (I noticed that the form is lengthy and submitting takes around a minute to complete).

If the problem persists, please let us know.