This can be due to the operators used in the query filter. 

For instance, if AND is used in a filter a record must meet that condition in addition to the ones before it.  AND excludes results if any condition is not met.

OR should be used instead when looking for the presence of one condition or the other, but not requiring both.

Fore more information review our how-to documentation for query tools.

If this does not resolve your issue Chat with Support and reference this article. .