Check to see if both of these properties are set to true

• incident.refresh_impacted.include_affected_cis
• change.refresh_impacted.include_affected_cis

If set to true, the configuration items on the related list "Affected CIs" will be evaluated against the svc_ci_assoc table.  If there are any Service Ids that are corresponding, then they will populate in related list Impact Services related list.

svc_ci_assoc is populated with Dynamic CI groups, and Application Service Population Methods

• Tag Based
• Service Mapping
• Dynamic CI Group
• Dynamic
• Manual (when a related link is used to populate based on the CMDB)