CONCAT should not show as part of lable, it should be just Assembly:03
This should be fix in ArcPro, labeling editor
https://transparentgov.net/json2tree/arcgis/js4/featurelayer_tree.html?layer_id=-99999&layer=RCA_Jurisdictions_072023&url=https%3A%2F%2Fodpsvcs.dot.ca.gov%2Farcgis%2Frest%2Fservices%2FRCA%2FRCA_Jurisdictions_072023%2FFeatureServer&_center_zoom=8&_center_lat=39.83468744206769&_center_long=-121.78670733694847&select_item_id=2&select_item_text=2+%26%23x21E2%3B+Assembly_Districts_Outline%3Csup+style%3D%22font-size%3A8px%22%3Epolygon%3C%2Fsup%3E&select_item_type=layer
All other layers has same problem,
senate, congressional, assembly
Warning: You have to zoom to certain level to show label
https://transparentgov.net/json2tree/esri/server/folder.html?org=https%3A%2F%2Fodpsvcs.dot.ca.gov%2Farcgis%2Frest%2Fservices&url=https%3A%2F%2Fodpsvcs.dot.ca.gov%2Farcgis%2Frest%2Fservices&arcgis_online_token=&select_folder=17&select_layer=-1