Sample state credential settings are configured to restrict sampling for a specific set of HCPs in a specific state. However, end users are still able to submit calls with samples for HCPs who should be restricted.
One possible cause of this issue is that the Credentials_vod field on the Sample State Credentials Settings record is not an exact match to the Credentials_vod value on the Account.
The Credentials_vod field on both records should be an exact match. Ensure that the correct values are enabled for the picklist on both objects and the correct value is selected.
CRM Help Documentation: Restricting Sampling by Account Credentials and State