Couldn't find a valid Google Service.plist

I have an Firebase project with 2 apps, same project ID, different bundle ID. The first created app works fine, but at the second one where I want to create some data to database, I retrieve this nice error:

Thread 1: " FirebaseApp.configure() could not find a valid GoogleService-Info.plist in your project. Please download one from https://console.firebase.google.com/."

I tried to modify the Workspace settings and many other things as some people said on Stackoverflow and GitHub, but none of them worked for me. Its not a syntactical problem like in the another topic where the issue was an lowercased “i”. I have also deleted the Google Service plist file from Build Phases → Copy Bundle resources and hasn’t worked either, I put it back after.

Two apps share the same project ID, I created the second app in the First app project, add pod files and so on, I dragged the Google Service plist file with copy items if needed checked in the app where is his place…So I have no idea what I have done wrong. I would have provided you with screenshots, but I hope I was detailed enough with this issue and is not needed.

Thank you!