Problem summary
Sponsored Brands works while Sponsored Products or Sponsored Display returns an access error.
Root cause
The root cause is unknown from this symptom alone. Account type, permissions, marketplace, KDP profile, and campaign activity are conditional checks. Do not treat them as likely or common causes unless the source settings or complete errors establish a match.
The Amazon Ads connector has account-type requirements for seller and vendor accounts. It also requires Admin or Editor permission for all Sponsored Ads report types. First confirm whether the working and failing sources use the same Amazon profile and Funnel credential. If they match, these connector-wide requirements do not explain the difference between report types. Different outcomes do not prove that the sources have different configurations or report-specific causes. They only identify the sources and errors that you must compare.
Solution
Compare the working and failing data sources' Amazon profile, marketplace region, account type and Funnel credential. Do not assume that they match.
Confirm that the connected Amazon user has Admin or Editor permission for each failing source. Viewer permission is not sufficient.
Record the complete error from each failing data source.
Check whether the exact error or profile matches a documented Amazon Ads condition in the related troubleshooting articles linked from Amazon Ads: Dimensions and metrics.
Apply a documented condition only when its required profile or exact error matches the failing source.
If the report-neutral settings match and no documented condition applies, contact Funnel support with the data source links, report types and complete errors.
Do not select a self-service fix based only on partial report access.