The following solution is only applicable for multi-center environments.

Confirm that you have multi-center: look at the top-right corner of your screen under your name. If you see “All Centers | Switch to another center” this means that your site is multi-center. Otherwise, you are not affected by this.

If the Security Category of your Query matches a center, then the Query can only select constituents within that center. To avoid this, change the Security Category to General.
  1. Go to Data Management > select Query
  2. Find your Query and click Edit
  3. Select the Query Info tab
  4. From the Security Category dropdown menu, select General
  5. Click Save