Not getting proper result by Search API

Hi everyone.

$searchQuery.Add("Query", "Testing alerts on staging for forum post")
$searchQuery.Add("FieldFacets", "category,count,12,0,0!0||user,count,12,0,1||group,count,12,0,1!1")
$searchQuery.Add("FieldFilters", $fieldfilters)
$searchQuery.Add("Collapse", true)
$searchQuery.Add("PageSize", $pageSize)
$searchQuery.Add("PageIndex", $ajaxCurrentIndex)
$searchQuery.Add("Tags", "ABC")
$searchQuery.Add("LogicallyOrTags", true)
#set ($results = $core_v2_searchResult.List($searchQuery))

NOTE: please ignore variables.

If i am running above code to search forum by text  "Testing alerts on staging for forum post" (this text is only contain by forum reply ). i am not getting data because reply does not contain ABC tag but forum thread contain ABC tag.

SO my question is, it is necessary that reply should also contain the same tag passed into search query.