Internal server error web 1.0

I have a web app on xojo cloud that I am developing/testing and have included an api to test.
The call to the api works IF I have connected to the app prior to making the api call, However if I make the api call when no one is connected to the app I get The Internal Server Error message.
I must be missing something as I’m not that web savvy.
Any pointers? TIA

I’ll take a look at your server in a few minutes.

I’ve sent you a private message.