Exchange Server 2019 Public Preview is still very new and yes it probably contains some errors/problems that should be addressed before the full release is issued.
In my lab, I came across the following error which is strange as the Server is pretty straight forward, no AV or Firewall enabled at stage of deployment.
A strange error popped up for NETSH and then disappeared. Here is a copy of the error:
Exchange Server component Mailbox role: Client Access service failed.
The following error was generated when “$error.Clear();
Enable-ExtendedTcpPortRange -Role “ClientAccess” -RoleIsDatacenter $RoleIsDatacenter
” was run: “Microsoft.Exchange.Configuration.Tasks.TaskException: Process execution failed with exit code -1073741502.
at Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)”.
If you re-run the setup again, it succeeds. Cannot find anything else regarding this error in the logs though.
Hope they fix it with the next update.
Hope it helps.