This can be caused when there are variations of an event. When selecting events for a view, users may use the IN or LIKE operators to find an event when searching by vendor message id. In some instances though, there are multiple instances of a single message id, as the message has been updated over time. In this instance, these newer messages will be identified in enVision with a :01 or :02 designation.

To be sure you are shown all the possible instances of a message id, use REGEX instead of IN or LIKE when searching for events to add to a view. This will result in all the versions of a message being displayed, and then you can select all possible version to ensure the event you want will be alerted upon.