Unable to log into self serve

Did you try the steps in the following link? https://www.koodomobile.com/en/help/problems-logging

Are you a prepaid or postpaid customer? If you're prepaid, self serve is a separate portal and the community reps here can't access prepaid accounts, you'd have to go through https://widget.telus.tiia.ai/koodoprepaid/koodoprepaid.html

As well, just to confirm, are you currently residing in Canada? Without VPN? And not using satellite internet? I ask since their security system might flag suspicious activity and not allow the password change to go through properly.

If that all checks out, I would recommend you clear the cache and saved passwords of your browser, then try again on a different device in incognito mode.