Some Action Log details (e.g. for a certain month) are missing in the list, what does it mean?
It may mean that UX1 panel wasn't enabled at that period.
Why do different statuses are shown for the same action made at the same date and time?
Some actions have one status, some actions might have several statuses, e.g. comleted and in progress. If an action has several statuses, all of those statuses will be reflected in the Action Log list.