A loop action every 15 seconds it starts ok but lately it runs every second

I have a loop in my MainActivity.java:

public class MainActivity <...> {
    Handler handler = new Handler();
    Runnable runnable;
    int delay = 15000;
}

@Override
public void onResume() {
    //super.onResume();

    handler.postDelayed(runnable = new Runnable() {
        public void run() {
            handler.postDelayed(runnable, delay);
            Log.d("myTag", "This is my message");
        }
    }, delay);
    super.onResume();

}

As said, at the beginning, the action runs every 15 seconds (not exact, sometimes 13, sometimes 16, etc., but as it keeps running) at some point starts to run every second:

Logcat of last entries:

2021-12-08 18:06:35.329 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:06:38.135 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:06:39.318 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:06:39.667 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:06:48.967 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:06:50.330 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:06:53.138 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:06:54.320 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:06:54.669 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:07:03.968 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:07:05.332 25533-25533/com.app.xxxx D/myTag: This is my message
2021-12-08 18:07:08.140 25533-25533/com.app.xxxx D/myTag: This is my message

Any ideas? Why is this happening?