Debugging Finance Report Performance Issues

Hello, 

We have issues with the performance of a finance report table. It takes a very long time to calculate the table when opening the Qlik app. Once cached in some way, the performance is good. We've tested the performance of the Qlik data model, dimension, and measure by converting the finance report into a native pivot table. The native pivot table calculates quickly. There is no calculated dimensions or pick functions in the measures. The issue is hard to reproduce 

Can you provide any insight into what processes may be happening to generate the chart when the app is first opened? Does it take so long due to an initial download of client files to generate the extension? Are the Qlik variables that support the extension created when the app is first opened? Any other tips on what else we can review to find out the issue and come up with solution?