FilteredStreamV2 - Why isn't TweetReceived raised?

[weirdyang]

I have two handlers for my filteredstream;

        private async Task SetupStream()
        {
            await _tweetConfig.CreateRules();
            _stream = Client.StreamsV2.CreateFilteredStream();


            _stream.TweetReceived += HandleTweet;
            _stream.EventReceived += HandleEvent;
 
        }

I noticed that the HandleEvent is called very often, but the HandleTweet method is seldom called. why is there a discrepancy? shouldn't there be an event with each tweet?