IOS build using both OneSignal cordova plugin and Flurry analytics fails

Hi Folks,

Our IOS build stopped working since we added the Flurry Analytics plugin to our Ionic4/Angular project.
We had this error: Plugins/onesignal-cordova-plugin/OneSignalPush.h:32:9: fatal error: ‘OneSignal/OneSignal.h’ file not found

The build works perfectly on Android

After a little bit of research, and hearing about a pod-related issue, we implemented the following solution : https://ionic.zendesk.com/hc/en-us/articles/360010049673-Managing-plugins-using-cocoapods-in-Ionic-Pro

Now we have this error : /Plugins/cordova-plugin-flurryanalytics/FlurryAnalyticsPlugin.m:1:9: ‘Flurry-iOS-SDK/Flurry.h’ file not found

Any idea ? this issue is driving me crazy !
Cheers,

cordova-ios: 5.0.1
onesignal-cordova-plugin: 2.6.0
cordova-plugin-flurryanalytics: 1.4.6