EsriMapMarkerField - Search location & Current location is not working

We're using the Esri Map component (esriMapMarkerField) from the plugin in Appian, integrated via an OAuth 2.0 "Other application" (client credentials) connected system pointing to ArcGIS Online. The map renders correctly with basemaps and drawing tools working fine, but the built-in address Search box fails with esri.widgets.Search.SearchViewModel console errors: suggest:no-sources-defined and search:no-sources-defined ("At least one source is required"). We confirmed the ArcGIS org has the World Geocoding Service properly assigned under Utility Services, and independently verified our Client ID/Secret generate a valid access token (tested via Appian's connected system "Test Connection" and manually via Postman). However, when the Search widget internally calls sharing/rest/portals/self to discover the org's default geocode source, the request returns a 498 Invalid token error — despite the token being valid when tested directly — suggesting the plugin isn't correctly attaching/propagating the token for this specific internal request. Has anyone encountered this specific gap between a working connected-system token and the Search widget's internal portal-discovery call failing with an invalid token, or found a workaround (e.g., manually specifying a locator/search source) within this Appian plugin?

 

a!localVariables(
  local!polygonCircle,
  local!polygonLine,
  local!polygon,
  esriMapMarkerField(
    esriConnectedSystem: cons!GVIS_CS_ESRI_MAP_CONNECTED_SYSTEM,
    baseMap: "osm",
    secondaryMap: "satellite",
    mapCenter: { latitude: - 25, longitude: 135 },
    trackCurrentLocation: true(),
    zoomLevel: 4,
    maxSelection: { pin: 0, polyline: 1, polygon: 1, circle: 1 },,
    onNewLineAdded: { a!save(local!polygonLine, save!value) },
    onNewPolygonAdded: { a!save(local!polygon, save!value) },
    onNewCircleAdded: { a!save(local!polygonCircle, save!value) },
    modifyGeometryType: true(),
    modifyGeometryColor: true()
  )
)