After I joined a Windows Server domain on my Surface Pro 3, I noticed that I must type my password to sign in every time my device is locked, even when "never require a password" is selected in PC settings, Accounts, Sign-in options. This happened whether I signed in to my non-domain or domain accounts. I unjoined the network domain, and it went back to the way before: I never had to type a password to sign in even when the device was locked. Is this by design? Does being in a network domain cause Win8.1 to heighten its security by requiring a password every time you sign in?