AAD B2C: After "reset password" from Azure Portal the B2C users cannot change it while loging in by SignIn policy URL.
If I (as AAD B2C admin) reset password to some user (type of Member in AAD) then thit user cannot change password using Sing-In Policy URL - the login form doesn't accept temporary password.
But if the user tries to log in to portal.azure.com with it's UPN and temp password - then password change works fine.