RATE FACTOR MEMORY PROCESSING: Why cannot it work w/o cache being cleared?

Summary:

Users forget to clear the cache after the fuel factor is added for the month.

The fuel accessorial does not get calculated for the month without the cache being cleared.

Shipments and invoice thereby does not have the fuel accessorial cost in them resulting in rework.

Content (required):

We have turned this parameter on ENABLE RATE FACTOR IN MEMORY PROCESSING.

It works great as long as the user does not forget to clear the cache after the fuel factor is added for next month.

Are we missing any step? Do other customers have to clear their cache too?

Trying to connect to as to why the cache not be loaded automatically.