Not sure if you ever resolved this for yourself, but for anyone else that stumbles across this question, I was able to resolve a similar issue by copying over the files from the “widgets” folder of an app made in Mendix 9 and paste them in the widgets folder of an app that was upgraded to v9 from v8.18.
I’m not sure why this needed to be done – I upgraded the various app store modules like NanoflowCommons, NativeMobileResources, and Atlas and then made sure to update the widgets within Studio, but kept running in to a bundling error with @react-native-community/netinfo within the AppEvents widget until I did this manual file replacement.
Hope this helps!