4. The agreement automatically ceases to have effect in the first pay period that follows the pay period during which one of the following situations occurs:
(1) any condition prescribed in section 1 is no longer met;
(2) the amount of the remuneration that is to be considered as having been paid to the employee is changed;
(3) the employee becomes, in accordance with the Act respecting the Québec Pension Plan (chapter R-9), the beneficiary of a disability pension or a retirement pension.