A security patch released on January 8 that fixed CVE-2019-0543 also inadvertently broke Windows PowerShell and Windows PowerShell Core 6 (PSCore6) WinRM based remoting for one specific PowerShell remoting scenario. The issue only affects local loopback remoting on endpoints where loopback endpoints are specifically configured to allow access to non-Administrator accounts. The fix is preventing WinRM (which Powershell uses as a remoting transport and host) from successfully creating the remote session host, for this particular scenario.
Source: https://www.bleepingcomputer.com/news/security/windows-security-patch-breaks-powershell-remoting/