By default case is ignored when running Queries against string columns. This is for Quick Search, Filters, and wherever we run a Query.
However, if this is not your preferred behaviour, you can set the the caseSensitiveTextComparisons property of General Options to be false (the default if not set is true).
This example we have set the value to false. Type 'j' into the Quick Search and you will see that Janet Leverling does not highlight. Change that to 'J' and it will highlight.