Okay, that is very likely that the pool sizes need to be manually adjusted then.
Go to the index table options, and click on the Performance & Accuracy panel. Then, change the options there like so: https://i.imgur.com/j9zcjV9.png
Save the options, and try the search again. If the results are still inaccurate, increase each field by 5000 each time. After some time, all of the expected results should come up. If the results are accurate, then you can lower the values gradually. The lowest values are better, as it caps the peformance.
