Optimizer's strange behaviour

Hi, i've got strange bug during optimization in ADS.

I've make schematic based on few SnP files and AMI model of FPGA Tx and Rx to perform SI analysis and optimize transciever parameters. So i've specify Tx and Rx AMI-parameters by variables, make them optimizable with discrete step, and run optimizer. When i check results i saw that otimizer calculate the same variables combinations many times in series (see picture). I've try different algoritms, and result same every time: calculating a few different combinations, then a lot of "one type" iterations, then, may be, change values and make another series of same calculations. Even if i use random algoritm.

Please can you help me with this issue

Regards,

Oriol