Fixed issue with filter form in data sources

Civi/DataProcessor/Source/AbstractSource.php

@@ -316,9 +316,9 @@ abstract class AbstractSource implements SourceInterface {
         if (!$fieldSpec) {
           $fieldSpec = $this->getAvailableFilterFields()->getFieldSpecificationByName($alias);
         }
-        if (isset($defaults[$fieldSpec->name.'_op'])) {
-          $defaults[$fieldSpec->name . '_op'] = $filter['op'];
-          $defaults[$fieldSpec->name . '_value'] = $filter['value'];
+        if (isset($filter['op'])) {
+          $defaults[$fieldSpec->name.'_op'] = $filter['op'];
+          $defaults[$fieldSpec->name.'_value'] = $filter['value'];
         }
         if (isset($filter['relative'])) {
           $defaults[$fieldSpec->name.'_relative'] = $filter['relative'];