Generally, non of the filter functions should return any results when you have leading spaces. The leading spaces should be part of the expression, so one should expect not to get any results.
Nevertheless, with our current implementation for the Contains
filter function, the searched string is trimmed and that is the reason for getting results with that function, but it is debatable if this is correct behavior or not.
As for your current scenario, the only things that I could suggest is that you trim your leading spaces from your database, inform the user that a leading spaces must be included when using EqualTo or to remove EqualTo from your filter options and leave only Contains.
Hope this helps.
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