The functionality to identify User Stories in Pivotal Tracker marked with the 'security' label is powerful. However, for the Tests to succeed, every US identified must have a priority. Pivotal Tracker has a built-in priority indicator, but this seems to be ignored by the integration. As a result, you need to provide an extra label (e.g. p0) to let Vanta know the priority.
As a result we now need to double document the priority, which is of course less efficient but more importantly can lead to inconsistencies, i.e. someone updates PT's build-in priority but forgets to update the label.