Timeline display duplicated track events in Insight Cloud UI

Description

If a user opens the Profile page from the profile list in the Insight UI, sometimes the timeline shows duplicated track events. This results in a count of aggregated daily events that exceeds the actual.

Step to reproduce:

1. From Insight, click a profile to open the timeline window.
2. Click the Show more button once if there are more events to load.
3. The daily number of track events is displayed in the timeline.
4. Click the show all link.
5. All events are listed.
6. Refresh the page.
7. Click the Show more button once if there are more events to load.
8. Click the show all link.
9. All events are listed.

Expected:
The same number of track events are displayed in the timeline for each day. The same events are listed - there are no duplicated events.

Actual:
Sometimes, there are fewer track events displayed in the timeline for some dates. Also, duplicated track events are listed before you refresh the page.