Android : Logcat not showing in Android Studio

I changed the applicationId of my app in build.gradle under app folder from

defaultConfig{
    applicationId "com.sample.sampleapp"
    ....
}

to

defaultConfig{
    applicationId "com.sample.app"
    ....
}

Now, the logcat is not showing even though the filter configuration is configured by package name: com.sample.app

Any ideas? Sorry, I'm new to Android Studio. Big thanks in advance.