[UI] The activity popup doesn't clear sometimes

While doing creating/dropping of the sample buckets on 7.1.0-2231 multiple times, I have observed that the activities in the Activity popup doesn't clear even after the activity is complete. See attached screenshot.

In this case, the activities for "loading sample : travel-sample" and "loading sample : gamesim-sample" are shown, but those activities are completed already. Similarly, there are activities for index building in progress shown, while they are completed too.

To reproduce, create a 1-node cluster with all services, and just install all sample buckets, and drop them after a while. Repeat these steps 2-3 times to hit the issue.