react-native: App terminated in background when WebSocket is open

I using WebSocket in my app when app move to background it terminated in short time, but I expect OS suspended app. Test on IOS 13.1.2 release mode

log from device

default	21:26:15.204466 +0300	SpringBoard	Firing exit handlers for 63390 with context <RBSProcessExitContext; specific: <RBSProcessExitStatus; domain: runningboard (15); code: 0x2182baad>; terminationContext: <RBSTerminateContext: 0x6000032f29c0; code: 0x2182BAAD; explanation: "Timed-out waiting for process [application<org.reactjs.native.example.test-bg>:63390] to invalidate assertion with identifier 4170-63390-4366 and explanation 'Shared Background Assertion 2 for org.reactjs.native.example.test-bg'. Direct this report to owners of that process"; reportType: 0; maxRole: 7; maxTerminationResistance: 3>>
default	21:26:15.207509 +0300	SpringBoard	[application<org.reactjs.native.example.test-bg>:63390]* Process exited: <RBSProcessExitContext; specific: <RBSProcessExitStatus; domain: runningboard (15); code: 0x2182baad>; terminationContext: <RBSTerminateContext: 0x6000032f29c0; code: 0x2182BAAD; explanation: "Timed-out waiting for process [application<org.reactjs.native.example.test-bg>:63390] to invalidate assertion with identifier 4170-63390-4366 and explanation 'Shared Background Assertion 2 for org.reactjs.native.example.test-bg'. Direct this report to owners of that process"; reportType: 0; maxRole: 7; maxTerminationResistance: 3>>.
default	21:26:15.207568 +0300	SpringBoard	[application<org.reactjs.native.example.test-bg>:63390]* Setting process task state to: Not Running
default	21:26:15.207611 +0300	SpringBoard	[application<org.reactjs.native.example.test-bg>:63390]* Setting process visibility to: Unknown
default	21:26:15.207704 +0300	SpringBoard	Removing: <FBApplicationProcess: 0x7feb8f7225d0; application<org.reactjs.native.example.test-bg>:63390>
default	21:26:15.207906 +0300	SpringBoard	Process exited: <FBApplicationProcess: 0x7feb8f7225d0; application<org.reactjs.native.example.test-bg>:63390> -> <RBSProcessExitContext; specific: <RBSProcessExitStatus; domain: runningboard (15); code: 0x2182baad>; terminationContext: <RBSTerminateContext: 0x6000032f29c0; code: 0x2182BAAD; explanation: "Timed-out waiting for process [application<org.reactjs.native.example.test-bg>:63390] to invalidate assertion with identifier 4170-63390-4366 and explanation 'Shared Background Assertion 2 for org.reactjs.native.example.test-bg'. Direct this report to owners of that process"; reportType: 0; maxRole: 7; maxTerminationResistance: 3>>
default	21:26:15.208345 +0300	SpringBoard	Application process state changed for org.reactjs.native.example.test-bg: (null)

full log https://github.com/fonov/rn-websocket/blob/master/device_log.txt

it look like socket can’t finished task and OS kill app

React Native version:

  IDEs:
    Xcode: 11.0/11A420a - /usr/bin/xcodebuild
  npmPackages:
    react: 16.9.0 => 16.9.0 
    react-native: 0.61.2 => 0.61.2 
  npmGlobalPackages:
    react-native-cli: 2.0.1

Steps To Reproduce

https://github.com/fonov/rn-websocket

i create fresh rn project and add this code

componentDidMount() {
    const ws = new WebSocket('wss://echo.websocket.org');

    ws.onopen = () => {
      ws.send('something');
    };

    ws.onmessage = e => {
      setTimeout(() => {
        ws.send('something');
      }, 1000);
    };

    ws.onerror = e => {
      // an error occurred
      console.warn(e.message);
    };

    ws.onclose = e => {
      // connection closed
      console.warn(e.code, e.reason);
    };
  }

in App.js

1. clone repo
2. run release app from the Home screen rather than from Xcode
3. go to home screen
4. wait a little bit and app is terminated