Monte Carlo with AMS

First of all, I am using "@(#)$CDS: virtuoso version ICADV12.3-64b 06/01/2017 15:59 (sjfhw311) $" and irun(64): 15.10-s002: (c) Copyright 1995-2015 Cadence Design Systems, Inc.

After watching this video https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1Od0000000519uEAA&pageName=ArticleContent, I believe that Monte Carlo should be supported by AMS.

I have created a Monte Carlo model like this:

parameters process_std=2.3e-6 mismatch_std=3.5

statistics {

process {

vary DV1 dist=gauss std=process_std percent=yes
}

mismatch {

vary DV1 dist=gauss std=mismatch_std percent=yes
}
}

where DV1 is a design variable. I have verified that Monte Carlo Run by pure Spectre within ADE-XL is fine and I can see the expected distribution in the result plots. irun+MentorGraphicAFS also has the expected results with the expected distribution. However, when I switch the simulator to AMS, the result plots do not vary as I expected. My question is how do I debug to see if the variable DV1 changes from one run to the other during the MC simulation.

Thanks,

TJ