I recently came a across an issue where I was unable to see a vector cache in a pdf when using a print service published to a standalone ArcGIS Server in Google Chrome. After debugging the issue with Esri Support. The solution was to create a print service via ArcGIS Pro, and publish it to ArcGIS Server. The only caveat is that ArcGIS Pro cannot publish Print Services and Geoprocessing Services to a standalone ArcGIS Server via the UI (it is possible if you know python). The ArcGIS Server must be federated with ArcGIS Portal. At the time I was instructed to use ArcGIS Pro to publish a print service to ArcGIS Portal, we did not have our portal up and running yet so this was not an option for us. Please allow ArcGIS Pro to publish Print Services and Geoprocessing Services to standalone ArcGIS Server as some of us are unable to embrace ArcGIS Portal at this time.