Form Validation and Disabled Button

I have tried using the disabled function of my button, but the form validation is not a predefined action i.e. the form widget has no state.
I have created 3 different page state - booleans verifying if each condition is valid but once again I do not find this criterion.

I have tried using the condition "Is Set and Not Empty" but it does not follow the validation criteria (if I type one letter into password, my button is not disabled anymore).

Any help would be much appreciated.
Have a great day!