Are exclusive jobs really exclusive?

Below is the extract from the ofiiicial document.

What are exclusive jobs?

“An exclusive job cannot be performed at the same time as another exclusive job from the same process instance. Consider the process shown above: if we declare the service tasks to be exclusive, the JobExecutor will make sure that the corresponding jobs are not executed concurrently. Instead, it will make sure that whenever it acquires an exclusive job from a certain process instance, it acquires all other exclusive jobs from the same process instance and delegate them to the same worker thread. This ensures sequential execution of the jobs”

As per my understanding this translates to "all exclusive job of same instance are executed same worker thread " . Expectation is … if i print the thread name from the parallel exclusive jobs. it should be same.

Actual behaviour is its not …
23:36:48.140 [e96a09ca1a48de13/e96a09ca1a48de13/] INFO
[ xxx-executor-4] s.g.n.i.f.h.MyClassHelper : 1d7222c2-63ae-11ea-8083-acde48001122. Thread Name >>xxx-executor-4
23:36:58.381 [b49f0260b90b8d8c/b49f0260b90b8d8c/] INFO
[ xxx-executor-6] s.g.n.i.f.h.MyClassHelper : 1d7222c2-63ae-11ea-8083-acde48001122 Thread Name >>xxx-executor-6

looks like the job executor is not delegating to same worker thread.
Any thoughts on this would be of great help. ?
Is there any specific process configuration which is disabling this behaviour ?

See The process engine does not run the exclusive tasks with the same java thread