Whenever I remove the "cordova-plugin-ionic": "5.4.7" from package.json, the error goes away and the platform.ready() fires correctly. I have tried removing then running the command 'ionic deploy add' according to the Appflow docs, but it just re-adds the plugin to the package.json.
I need to get rid of this error because it messes with the device ready event, causing the functions inside it to not run. My quick fix was to call the functions outside the platform.ready but it is not a true fix. Been searching for this for quite a while now.
Remove your ios/android folders as well when you remove cordova-plugin-ionic. then add your platforms first, followed by ionic deploy add. This will put the configurations correctly.
If you are working on Capacitor v2, it will work.