The error was related to the way I did import the dependencies on Gradle.
Before:
androidTestImplementation("androidx.fragment:fragment-testing:1.1.0-beta01")
implementation("androidx.fragment:fragment-ktx:1.1.0-beta01")
androidTestImplementation("androidx.test:core:1.2.0")
androidTestImplementation("androidx.test:rules:1.2.0")
androidTestImplementation("androidx.test:runner:1.2.0")
After:
debugImplementation("androidx.fragment:fragment-testing:1.1.0-beta01")
debugImplementation("androidx.fragment:fragment-ktx:1.1.0-beta01")
debugImplementation("androidx.test:core:1.2.0")
debugImplementation("androidx.test:rules:1.2.0")
debugImplementation("androidx.test:runner:1.2.0")
Changed from androidTestImplementation to debugImplementation and it solved the issue. Compiling and running, and green test as result.