By default, the plugin caches all closed sprint reports because in most cases it is a permanent entity. You can disable the cache feature in the settings at any moment but it may cause a load slowdown for sprint reports which contain a big amount of tickets.
When the cache is enabled and JQL filter is filled you should be careful because JQL can be temporal, with now() and sla (https://confluence.atlassian.com/servicemanagementserver/using-jql-queries-specific-to-slas-939926424.html) being good examples of these, often being compared to fields such as created.
Example:
if you cache on with jql expression - "Time to resolution" < remaining ("2h") the cached results can be expired immediately because remaining time is not a static value and changes in time.
More examples of "fast expired" JQL expressions
created <= -5dchanged <= -5d"Time to first response" < elapsed("10m")
For all the above cases, we recommend switching off the cache feature