The WFA Cache does need to be flushed. If you select Workflow Cache Group, choose a date/time, then click Schedule Cache Flush, it should show up in the table below. If it doesn't, and the Refresh button doesn't do it either, check the Event Logs and see if something is added there.
If your item does show up, and you click on the datetime blue link, this should pop up a details window, in which you should see and Linear Workflow Service entry. If you have an app running, like GSM, that cache request should get picked up.