You have to look at the "Forecast Age" on "Track Designer Settings" group.
One minute before the wind change, it must look like 11:59:00.
One minute after the wind change, it should be 00:01:00.
You can choose the first option [x]Time from Last wind update
Set time to first wind update
time (use local time).
If the Forecast Age is wrong, weather routing and track designer
will produce wrong results.
The "Time stamp + time zone" option seems to be wrong for this race.