Intermittent http POST request errors

So I’m trying to insert data into a database via http POST from my iOS app, and… it works about 30% of the time. The remaining time I’m getting this back from the server:

[“error”: {
errorGroup = User;
name = JsonSyntaxError;
}]

(the first of my 4 database fields is called ‘name’, which is a string- the rest are all numbers)

Thing is, I’ve written a test function to resubmit exactly the same POST request data repeatedly so I’m sure (to the best of my knowledge) that the JSON I’m sending it is fine, but as I say it only works about 30% of the time, the remaining time I get this syntax error response.

Here’s what I’m using to on the Wix side:

export function post_scoreboard(request) {
 let options = {
 "headers": {
 "Content-Type": "application/json"
    }
  };
 // get the request body
 return request.body.json()

  .then( (body) => {

 // insert the item 
 return wixData.insert("Scoreboard", body);
    } )
    .then( (results) => {
      options.body = {
 "inserted": results
      };
 return created(options);
    } )
 // something went wrong
    .catch( (error) => {
      options.body = {
 "error": error
      };
 return serverError(options);
    } );
}