Fitness sets wrong time for 1/2 and Full Marathons?

How after so long has Apple not fixed the fact that fitness incorrectly reports half and full marathon times. It seems to pick the time for a distance 1km shorter than the actual distance.

Apple you have to fix this! It must be simple to include in an update - it ruins it for stats tracking

I am running the latest software on all devices.

anyone know a work around?