Hopefully this helps someone save a few hours of scratching their head…
Either my Google skills are failing me or no one has posted this in a place I can find. Today I was trying to use an automatic transition based on criteria I had set in a previous transition using the Set Variable action. Everything seemed fine, but alas, I couldn’t get the auto transition to trigger. I checked the database, and sure enough, no variables were set. Maybe I forgot to save the workflow that was setting the variable- resave and retry… nope. Not it. After searching for the answer and not finding it, I decided to add a hidden tab to the data card for this filetype and show the variable I was setting. BOOM. All is well and my transition criteria is met and my auto transitions run.
TLDR:
Transition Action Set Variable requires the data card to have the variable on it (can be hidden by control logic or another means) to be added as a variable value.
Side note:
Searching for variables through a search card also requires that a variable is a part of the card.