Performance to zoom in and out on a Symbol Map showing the US west coast takes 9-10 seconds. It is published to Tableau Server 10.5 and uses published data extracts.
Performance to zoom in and out on the same Symbol Map using Tableau Desktop takes 1 second using same workbook and published extracts. For my testing, Tableau desktop runs on the same app server that Tableau Server runs on.
I'm guessing that there is some issue getting to the map site on the internet when the workbook is published to Tableau Server that does not exists when using Tableau Desktop.
Any thoughts? Sorry, I cannot include the workbook as it has confidential info.
This could be more associated with the Tableau Server and the resources availbe to display the map.
I would review this community post on slow rendering maps: Slow rendering maps
Hope this helps!