If a user reports that they cannot log into AngelPoints and they have SSO, they must check on the URL they are using to access their volunteer portal, which email account is tied to the AngelPoints account, and the level of security attributed to the account. If those check out, then it is likely an issue with the SSO token they are using to log into their employee portal.
A surefire way to know if the issue is AngelPoints-related or SSO-related is if you are prompted to log in, what specific site refuses your entry? If it is the AngelPoints site, something may be amiss with your profile. If it is the employee portal, then this has to do with SSO and must be handled by the internal IT team.