ERROR: Plugin 'map_0_1298011159248' not found, or is not a CDVPlugin. Check your plugin mapping in config.xml.

**I'm submitting a ...** (check one with "x")
- [ ] question
- [x] any problem or bug report
- [ ] feature request

**If you choose 'problem or bug report', please select OS:** (check one with "x")
- [ ] **Android**
- [x] **iOS**
- [ ] **Browser**

**cordova information:** (run `$> cordova plugin list`)

```
com.googlemaps.ios 3.9.0 "Google Maps SDK for iOS"
cordova-plugin-device 2.0.3 "Device"
cordova-plugin-fcm-with-dependecy-updated 7.1.1 "Cordova FCM Push Plugin"
cordova-plugin-googlemaps 2.8.0-20200709-2008 "cordova-plugin-googlemaps"
cordova-plugin-inappbrowser 4.0.0 "InAppBrowser"
cordova-plugin-ionic-keyboard 2.2.0 "cordova-plugin-ionic-keyboard"
cordova-plugin-ionic-webview 5.0.0 "cordova-plugin-ionic-webview"
cordova-plugin-network-information 2.0.2 "Network Information"
cordova-plugin-splashscreen 6.0.0 "Splashscreen"
cordova-plugin-statusbar 2.4.3 "StatusBar"
cordova-plugin-whitelist 1.3.4 "Whitelist"
```

**If you use `@ionic-native/google-maps`, please tell the package.json (only `@ionic-native/core` and `@ionic-native/google-maps` are fine mostly)**

```
"@ionic-native/core": "^5.27.0",
"@ionic-native/google-maps": "^5.27.0-beta-20200630",
"cordova-plugin-googlemaps": "git+https://github.com/mapsplugin/cordova-plugin-googlemaps.git#multiple_maps",
"cordova-plugin-googlemaps-sdk": "git+https://github.com/mapsplugin/cordova-plugin-googlemaps-sdk.git",
```

**Current behavior:**
I migrated an app from ionic 3 to ionic 5, so now I'm using ionic 5 and the map works well in browser but it doesn't work on iOS (13.4.1) I get a grey screen instead of the map.
This is the console log in xcode while the simulator is running:

```
2020-08-20 12:09:28.788995+0200 AppAgentiMangimiLiverini[13471:133837] ERROR: Plugin 'map_0_867075012460' not found, or is not a CDVPlugin. Check your plugin mapping in config.xml.
2020-08-20 12:09:28.789427+0200 AppAgentiMangimiLiverini[13471:133837] FAILED pluginJSON = ["INVALID","map_0_867075012460","detachFromWebView",[]]
2020-08-20 12:09:28.866537+0200 AppAgentiMangimiLiverini[13471:133837] background = #dfdfdf
```

The Google API key is correct, it works with the app in ionic 3.

**Expected behavior:**
That it works on iOS.

Thanks