admin/user password incorrect only in terminal

so ive had this issue for a couple years actually but never really needed to use terminal, now im fully upgrading my studio computer to high sierra and am trying to disable gatekeeper completely (i know the risks) the issue like so many other people have is the admin password is "incorrect" i do not have textexpander installed, my password is very simple with no strange characters, whats weird is this has plagued my computer for years and years and even on a full clean install i still get incorrect password in terminal. whats going on here? its making me think theres something deeper going on, whats also weird is my 2012 macbook pro does not show the same behavior even on the same OS. (this issue os on my original cmacpro 5.1)