Fixing timeout issues
Callisto expects data for all charts and dashboards to be returned within a central timeout of 30 seconds. Generally this works fine, but for very large environments, or where Callisto is network-distant from the SQL database it may be necessary to extend this timeout limit.
Callisto 20-05 introduced a custom timeout option to allow the administrator to override the default timeout window.
Navigate to Administration - Settings and scroll to the bottom of the page.
Add a value up to 300 seconds (5 minutes) and click save.