What is the ghost account? Does it have a name? Can I see a picture?
Did you enable the built-in hidden Administrator?
As to the MS account appearing on Log-In screen asking for PIN after setting it to skip password, does a link appear nearby to change Sign-in Options, so you can change it to Password?
Did you use fresh installation media for the latest version, wipe all partitions off the drive, not do any other hacks or modifications whatsoever, expedite all Windows Updates until no others are offered, then import the latest drivers and BIOS from the PC maker's Support Downloads webpage for your exact model. While there check for the latest Chipset, BIOS, Sound, Network, USB3, Bluetooth and all other drivers to compare with the version/date installled for that device in Device Manager reached by right clicking the Start Menu.