Obviously Commsec have adapted their system and are now using NXXT trades to match with other Commsec orders.
I am sure they are saving some money and as far as they are concerned - tough for retail traders that last price and order alerts are not triggered.
How the ASX was able to define these types of trades to behave like this (volume/vwap/last price effect) with apparently NO CONSULTATION with retail market players (as far as my broker is concerned) is beyond me!