If you generate a Work Management-Idlers report and it shows no failures, but you know there are some recorded, were they recently recorded using a PDA? If so, try putting -1 in the Days in Failure field as shown below.
As per our end of feature notice (see below), the PDA's don't cope with UTC time, which is something we added to our software to cater to international customers. The PDA can only save using local time instead of UTC, which means that the timestamp for records is out by 8hrs in W.A., or 11 hours in NSW. This results in idler failures being stored with a future date/time, which is why entering -1 is a workaround for this issue.