All our platforms are Single Sign On (SSO) which means you always use the same password, the student/employee portal password. Only change your password from the password reset portal, you cannot do so from Moodle, Gmail etc.
Here are some links to help: Student Login issue - Portal/Moodle/D2L/Gmail
: Employees (All Staff & Faculty) Login issues - Portal/Moodle/D2L/Gmail