Prior to the release of the full version on September 19, the service will be modified to disable the network versus function of the DEMO version.
Please enjoy online matches with the retail version thereafter.
About the suspension of communication functions in the DEMO version
Source: Steam Community (opens in a new tab)
Build and release context
Recorded Steam release date:
Within one calendar day of this post (UTC). The listed date does not establish an exact launch time.