Login Restriction PS4

I used my dads PS4 to try and play the game under my own Playstation account ofcourse. I put in the game it updated on his machine, the login came up it had my login ID from square enix in the box already, like always, but when i entered my password CORRETLY, with my square enix account and PS account linked together mind you, it was "suspicious activity" and my account was suspended. Am I going to be forced into a password change everytime I switch machines? if so whats the point of linking my accounts together. it takes one password to get on to the PS acount an another for square enix, and thats not enough to prove that I am that one who bought this game and the time for it?

Yes, everytime you switch IP's. If you add a token, it gets rid of the problem all together. Unless, say, you're logged in from home one second, and then in Russia the next.