If I recall correctly, the ChM Change Open notification is called whenever a new phase is opened, not only when the change is opened--the notification you're seeing is not a result of the logging phase being closed, but is instead generated by the next phase being opened. Similarly, the closure notification definition is called at phase closure, not just at final closure of the change. I don't have access to a non-PD Change build, so I cannot test.
Please post a screen capture of the notification definition for review.
John's explanation helped me to understand when it fires. I looked at the condition and picked up that it was approval.satus="pending" that was why it was firing when it changed phases. I've attached a copy of Chm Change Open to show this but what I really want is for Chm Change Approval to work.
I can't figure out why Chm Change Open works (and sends to all members of the current.pending.groups setting) but the similar line in Chm Change Approval doesn't. Is one condition in the notification cancelling out another?
Unfortunately we're not using Process Designer for Change yet but demos of this from HP seem to greatly simplify setting up conditions within workflows.
If a change has multiple approvals, ChM Change Approval fires as EACH approval is executed, which does not necessarily mean that the change has been approved (there may still be additional pending approvals).
--If you add an approver notification to this notification definition, the remaining approvers can be sent another approval request after each group approves.
ChM Final approval is called when all approvals are completed and the record approval status changes to approved.
Your initial approver notification should be based on ChM Open.