This article explains the issue wherein the UI shows "First byte received/Min response time/Average response time/Max response time/Size/Rate" getting recorded but we can see the timeout to be 100% as well as no response being received.

First byte received/Min response time/Average response time/Max response time/Size/Rate are still being recorded even though the timeout is 100% and no response is being received as well.

The ES timeout will show the previous test results if for the current time period, these metrics cannot be measured.

Hence for the timeout event, you still see metrics on the UI but they actually are from the previous test results for which it was successful and not timed out.

In such cases, you must check ES (errored seconds) as well to detect errors. ES 100% means the time interval does not have any valid results and hence will display the previous test results.