Apple ID password doesn't work when tried to log in on Mac!

Hello! I hope someone can help me with this.
The thing is when I try to buy something from the itunes store or app store from my mac, it ask for my password, obviously, which I provide. But the thing is it doesn't log in, it just ask for it again, and again, and again, and again, and again and it goes on for as long as i keep writing the password.
If it's the correct password, it doesn't say anything just put the square thing back for me to write the password again, but if it's incorrect the square comes back saying the password was incorrect.
I tried resetting everything on my mac, and even changed my password 5 times, but it still not working.

The only time the password worked was when I logged in for the very first time, when I bought it, so the updates of the preinstalled programs are downloaded automatically, but I haven't been able to download anything else that requires for me to put the password again.
But it works perfectly fine on iPhone, iPad, and browsers.
Thanks in advance.