Gradle: "Could not resolve com.google.guava:guava:33.3.1-android "?

Question

I'm using Gradle 6.9 (this git project won't build on anything >= Gradle 7 so the Gradle has to be 6.9 or lower). It also failed w/ the same error using Gradle 6.8.3.

Here is the error when I gradle clean build :

Task :wallet:preDevDebugBuild FAILED
FAILURE: Build failed with an exception.
What went wrong:
Execution failed for task ':wallet:preDevDebugBuild'.
  Could not resolve all files for configuration ':wallet:devDebugCompileClasspath'.
     Could not resolve com.google.guava:guava:33.3.1-android.
     Required by:
         project :wallet
        The consumer was configured to find an API of a component, as well as attribute 'com.android.build.api.attributes.BuildTypeAttr' with value 'debug', attribute 'flavor' with value 'dev', attribute 'com.android.build.gradle.internal.dependency.AndroidTypeAttr' with value 'Aar'. However we cannot choose between the following variants of com.google.guava:guava:33.3.1-android:
          - androidApiElements
          - jreApiElements
 

I have tried referencing other repositiories in my project level build.gradle. All have failed :

buildscript {
    repositories {
//      mavenLocal()
        //maven { url "https://repo1.maven.org/maven2" }
        
        
        mavenCentral()
        google()
    }

}

allprojects {
    repositories {
//      mavenLocal()
//      maven { url "https://repo1.maven.org/maven2" }
        mavenCentral()
        google()
    }
}

Here are my (some) subproject dependencies (edited for brevity):

dependencies {
    implementation 'org.bitcoinj:bitcoinj-core:0.16.4'
    implementation 'com.google.guava:guava:33.3.1-android'
    // https://mvnrepository.com/artifact/com.google.guava/guava
    //implementation 'com.google.guava:guava:33.4.0-android'

    implementation 'com.squareup.moshi:moshi:1.11.0'
    implementation 'org.slf4j:slf4j-api:2.0.9'
    implementation 'com.github.tony19:logback-android:3.0.0'
}

I know the artifact exists: https://repo1.maven.org/maven2/com/google/guava/guava/33.3.1-android/

and... https://central.sonatype.com/artifact/com.google.guava/guava/33.3.1-android/versions

Is this a repository problem? Or is it due to me lacking some Gradle skills?