Watopia full lap

Hi, I was riding last night and thought I’d go for a fast lap, however I couldn’t figure out how timing worked on the lap. As I went under the start line I got the usual timer at the top of the screen. However when I then came towards the end of the lap, the time suddenly changed (down from what it was)? 

You don’t see your current lap time until something like 100m till the end of your current lap. the lap time your trying to beet changes as soon as you are slower than the fastest time, it then shows you the next fastest time to beet etc etc.

Like time trial timing on the telly