Firebase Crashlytics - crash reports won't de-obfuscate

Question

I have recently integrated Firebase Crashlytics to my KMM app and set up a release build with obfuscation. I followed the official documentation (https://firebase.google.com/docs/crashlytics/get-deobfuscated-reports?platform=android) in order to obtain readable reports in Crashlytics dashboard for obfuscated builds, but I still get obfuscated errors.

Here is my build.gradle.kts release build setup:

   getByName("release") {
        isDebuggable = true
        isMinifyEnabled = true
        configure<com.google.firebase.crashlytics.buildtools.gradle.CrashlyticsExtension> {
            mappingFileUploadEnabled = true
        }
        proguardFiles(
            getDefaultProguardFile("proguard-android-optimize.txt"),
            "proguard/crashlytics.pro"
        )
    }

And my crashlytics.pro file

-keepattributes SourceFile,LineNumberTable        # Keep file names and line numbers.
-keep public class * extends java.lang.Exception  # Optional: Keep custom exceptions.

I am using Firebase BoM version 29.3.0.