JQL function testsWithTestSetVersion returns data intermittently.

We are using following JQL which intermittently returns the data:

issuetype = Test AND issue in testsWithTestSetVersion(ORP, Prototype1_Iteration3) AND Prototype = "Prototype 1" AND Iteration = "Iteration 3" AND Status != Canceled AND TestRunStatus not in (DEFERRED, OBSOLETE)
issuetype = Test AND issue in testsWithTestSetVersion(ORP, Prototype1_Iteration2) AND Prototype = "Prototype 1" AND Iteration = "Iteration 2" AND Status != Canceled AND TestRunStatus not in (DEFERRED, OBSOLETE)
issuetype = Test AND issue in testsWithTestSetVersion(ORP, Prototype1_Iteration1) AND Prototype = "Prototype 1" AND Iteration = "Iteration 1" AND Status != Canceled AND TestRunStatus not in (DEFERRED, OBSOLETE)