react-native: [TypeError: Network request failed] using fetch, iOS only issue

Description

I cant reach my API on iOS emulator. The same code runs perfectly on the Android emulator. I tried a couple of other APIs just to test and everything works as intended (JSONPlaceholder with HTTPS and some random one that uses HTTP. Both GET and POST work fine).

React Native version:

System: OS: macOS Mojave 10.14.6 CPU: (4) x64 Intel® Core™ i5-5257U CPU @ 2.70GHz Memory: 31.91 MB / 8.00 GB Shell: 5.3 - /bin/zsh Binaries: Node: 14.6.0 - ~/.nvm/versions/node/v14.6.0/bin/node Yarn: 1.22.5 - /usr/local/bin/yarn npm: 6.14.6 - ~/.nvm/versions/node/v14.6.0/bin/npm Watchman: 4.9.0 - /usr/local/bin/watchman Managers: CocoaPods: 1.9.3 - /usr/local/bin/pod SDKs: iOS SDK: Platforms: iOS 13.2, DriverKit 19.0, macOS 10.15, tvOS 13.2, watchOS 6.1 Android SDK: API Levels: 28, 29, 30 Build Tools: 28.0.3, 29.0.2, 30.0.2 System Images: android-29 | Intel x86 Atom_64, android-30 | Google APIs Intel x86 Atom Android NDK: Not Found IDEs: Android Studio: 4.0 AI-193.6911.18.40.6626763 Xcode: 11.3.1/11C505 - /usr/bin/xcodebuild Languages: Java: 1.8.0_265 - /usr/bin/javac Python: 2.7.16 - /usr/bin/python npmPackages: @react-native-community/cli: Not Found react: 16.13.1 => 16.13.1 react-native: 0.63.2 => 0.63.2 react-native-macos: Not Found npmGlobalPackages: react-native: Not Found

Expected Results

I would expect the same request to go through on both platforms as per usual.

Code example and error screenshot:

const login = async (authData) => {
  console.log('fetching...');
  //Setting up the request
  //Select apropriate port 8515 | 8516
  const port = handlePortSelection(authData.username);
  const url = `http:\\xxx.xxx.xxx.xxx:${port}/api/Auth/LoginUser`;

  const headers = {'Content-Type': 'application/json; charset=UTF-8'};

  const body = JSON.stringify(authData);

  const requestOptions = {
    method: 'POST',
    headers: headers,
    body: body
  };

  try {
    //Call API
    const response = await fetch(url, requestOptions);

    const data = await response.json();

    setUserData(data);
  } catch (error) {
    console.error(error);
  }
};

My Info.plist file:

    <dict>
        <key>NSAllowsArbitraryLoads</key>
        <true/>
        <key>NSExceptionDomains</key>
        <dict>
            <key>localhost</key>
            <dict>
                <key>NSExceptionAllowsInsecureHTTPLoads</key>
                <true/>
            </dict>
        </dict>
    </dict>