Automation "Adjust Order Weight" not functional.

I have several automation rules set up with the action "Adjust Order Weight" and I cannot get it to work.  The criteria are being met, the log shows the rule as "applied", and the other actions in the rule are working, but the order weight is never adjusted.  I have reached out to support, but its been a week and I have not yet received a response (this appears to be typical). Anyone else having this problem or any ideas what could be causing it? Thanks!