Hey @Joe459
In order to have access to Polygon data, you must have a funded live trading account. Any Alpaca user, solely paper-traders included, has access to IEX data. In your screenshot you are connected to the paper trading endpoint and therefore you will be receiving data from IEX data which does not include trades from all the exchanges Polygon does. (More information concerning this can be found on this post Help with Barset). This could be the reason you are seeing less volume when streaming.
Hope this helps,
Jason