Also, Deployment Monitor app at the license master also should show historical indexed volume if it is enabled. Please keep in mind that the Deployment Monitor's all view should work properly only when the license master is a search head of all the license slaves. Otherwise, some dashboards information is not proper.
The violations are reported every time because it's not specific to one indexer, but to the pool.
you also may have older violations (if indexers were they own master before, and were added to the pool with their own violations )