react-relay somtimes gives response and somtimes gives network failure

TypeError: Network request failed
at EventTarget.xhr.onerror (C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\whatwg-fetch\dist\fetch.umd.js:473)
at EventTarget.dispatchEvent (C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\event-target-shim\dist\event-target-shim.js:818)
at EventTarget.setReadyState (C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\react-native\Libraries\Network\XMLHttpRequest.js:575)
at EventTarget.__didCompleteResponse (C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\react-native\Libraries\Network\XMLHttpRequest.js:389)
at C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\react-native\Libraries\Network\XMLHttpRequest.js:502
at RCTDeviceEventEmitter.emit (C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\react-native\Libraries\vendor\emitter\EventEmitter.js:189)
at MessageQueue.__callFunction (C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:425)
at C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:112
at MessageQueue.__guard (C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:373)
at MessageQueue.callFunctionReturnFlushedQueue (C:\Users\DELL\Desktop\projects\app-beyond-the-bogey-development\node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:111)
My graphql is working on localhost:8082