iff on coverpoint block effecting another coverpoint with transition in the same group

 Hi,

I have a coverage group defined as below:

   covergroup ready2 @ (negedge clk);
      ready : coverpoint dataReady iff ! enable {

         bins is2 = {2};
         bins is1 = {1};
      }
      ready2 : coverpoint dataReady iff enable {
         bins is2 = {2};
         bins is1 = {1};
      }
      ready_trans : coverpoint dataReady iff enable {
         bins two2one = (2=>1);
         bins one2two = (1=>2);
      }

I did not get any coverage on ready_trans

However, if I put 'iff' on bins, then everything works as expected:

   covergroup ready @ (negedge clk);
      ready : coverpoint dataReady {
         bins is2 = {2} iff !enable;
         bins is1 = {1} iff !enable;
      }
      ready2 : coverpoint dataReady iff enable {
         bins is2 = {2};
         bins is1 = {1};
      }
      ready_trans : coverpoint dataReady iff enable {
         bins two2one = (2=>1);
         bins one2two = (1=>2);
      }

   endgroup // ready                                                                                                                                                              
 

Unless my understanding of 'iff' usage is not correct, I do not see how the 2 cases are different.

This is compiled and run with 'irun' version 08.20-s012.

Any  helps or tips would be appreciated.

Dam