Unix cron expression not taking seconds in consideration

Cron expressions like -> (`*/2 * * * *`) are supposed to run every two minutes from a scheduler that checks every 10 second if now is the execution time using

`ExecutionTime.isMatch(ZonedDateTime zd)`

**Issue :**
In the 2nd , 4th , 6th ...... minute, the **isMatch(date)** method returns true for each of the 10th second in that particular minute.
So cron expression runs 6 time instead of 1 time.

So my query was, is it like that only ? or I am making any mistake ?

Need help with this.

**Note :** Also I tried to build the code from latest branch(9.1.5) as well from the master branch. It didn't build properly.
Tests are failing.