The search fails because nested analytics queries require the outer query attribute type to match the inner query display-column data type. The FortiSIEM Study Guide explicitly explains this rule in the Nested Query section: “Another important aspect to understand is that the data value types must match.” It further explains that each inner query display column has a data value type, such as IP, string, or integer, and the outer query attribute must match that type. The FortiSIEM 7.4 User Guide states the same operational requirement: for a nested query to work correctly, “the data type of the filter attribute in the outer query must match up with the data type of one certain display column in the inner query.” Therefore, if the inner query returns a string attribute but the outer query compares it against an IP-type attribute, FortiSIEM cannot produce a valid match. The issue is not the time range, not the use of User and Event Type together, and not the Boolean operator. It is an attribute type mismatch between the query and subquery.