I am going to move this post to Server Administration but have you tried the suggestions here to refresh more often? - Data in a Tableau Server View is Out of Date | Tableau Software
I hope this helps,
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Is sounds like you're hitting the cache. Try the following:
Tabcmd get /views/customerservicedata/customerhandling.png?refresh=true -f customerhandling.png
Now be mindful of using the parameter, ?refresh=true , because you can really bang on your server. Please test this out before implementing a massive download.
To really find out if you are hitting your cache and your server resource usage I highly would recommend Logshark. Specifically the plugins ResourceManager and VizqlServerPerformance.