I am having a very similar problem to this one: https://help.zoho.com/portal/community/topic/workflow-rule-not-firing.

I'm trying to set a secondary "Deal Stage" picklist field whenever Stage is updated so that I can then present a "Phase" picklist dependent on Stage.

I've added an e-mail action to the workflow as suggested. Even though the record timeline says that the workflow ran and that the e-mail and function executed, the Deal Stage field remains unset and the e-mail unsent.

here's the function:

Deals is the name of the Potentials table, confirmed as per Kevin Flynn's instructions.

dealID is an argument which passes the record ID to the function.

stage is an argument which passes the Stage to the function.

The Workflow rule is set to execute whenever Stage is updated.

The rule is executed for all Deals.

According to the workflow usage, there have been zero failures. Likewise, Setup > Actions > Functions reports no failures.

Thanks in advance for any guidance you can provide.

Peter