Server 2019 %username%

Running Server 2019 I've noticed that the %username% variable is now set to SYSTEM.  With Server 2016, when a user runs a batch file I can use the %username% variable to return the name of the user running the session.  However, with Server 2019, when a user runs a batch, the %username% variable returns as SYSTEM.

I'm getting around this by parsing %userprofile% to find the name.  Should we expect this to be a change in how Server 2019 operates?

I should note that I am running build 17723.