Service Calling problem Ionic

Hey, I am using a service to get last ID and Username from a JSON URL.
It was working great, but suddenly it stopped working. When i install the application on a device, first time it displays result correctly but doesn’t show next entry instead it shows that 1st entry again and again.

My service is: http://server2.a2zcreatorz.com/staging/projects/bayer-survey/bayer/fetchsurveyeeid.php
My calling method:

Thank You