You would have to most probably change the behavior of the dataset that is to be cached. This also changes the report to a cached model regardless of any report setting.
Actually, this is how it works by design.
KPIs always use cached data regardless of any setting applied on a particular dataset.
The workaround is to just set up a scheduled cache refresh. In order to resolve this, we can just set up a scheduled cache refresh plan that keeps on updating the cache every 10 minutes during business hours and this should work fine