Discrepancy in Query Analytics Data

I have some doubts regarding QAN dashboard in PMM. There is some discrepancy in data shown.

Here it says query is taking 16.97 seconds, but when I tried running the query, it actually fetches the data within a second or so.

Also in the second Image,

I am not able to understand what does total query time of 278.81ms means, when one query is taking 16.97 seconds.