### Steps to reproduce

1. Edit work packages in the series backlog (adding/removing, editing, re-ordering)

2. In parallel, go to another occurence of the meeting


### What is the buggy behavior?

* Begin of the insertionEditing a backlog item sometimes triggers the flash in the first meeting

* End of the insertion The 'meeting update' flash sometimes shows up in the second meeting, sometimes doesn't


### What is the expected behavior?

* Only show the flash if changes affect _the current_ Begin of the insertionoccurence, ie, moving items in and out of the backlogEnd of the insertion Begin of the deletion occurenceEnd of the deletion