React Native version mismatch 0.59.1 > 0.61.2

After creating a new bundle.js with "build:ios": "react-native bundle --entry-file='index.js' --bundle-output='./ios/main.jsbundle' --dev=true --platform='ios'", it worked.

Update

This fix above only fixed a part of the issue. I noticed that after manually creating the iOS bundle, React Native did not create a new bundle on load/refresh. That was my first clue which reminded me in some changes I made in AppDelegate.m:

#if DEBUG
  return [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index" fallbackResource:nil];
#else
  return [[NSBundle mainBundle] URLForResource:@"main" withExtension:@"jsbundle"];
#endif

After changing back the else statement to what I had before return [CodePush bundleURL]; it fixed the issue. I'm not sure what caused me to change it in the first place, I think it was the Codepush documentation.