PX policies triggering on data elements of type Task/Event Info Unique Name are not firing when expected on any system other than production.
Unique name is an internal unique ID number give to each individual task in an Identity Manager environment's object store internally.
The problem here is that is can be different from server to server. For example the task called "Modify User" may have a unique name of 391 in production, but that same task has the unique value 473 in staging.
Setting up entry rules based on the 391 value will only work in production, given this fact.
Modify the action entry rule on the PX policy to use Task/Event Info>Friendly Name or Task Tag instead, as this does not change from IM instance to instance.