I would think that if there is live data in instrument cluster for Vehicle speed and the speedo isn't working, then the cluster must be faulty. ?? ( I Could always be completely wrong )

I had a similar fault on a Peugeot fuel gauge where the live data showed ok in cluster but the gauge didn't read, But it would work using Actuator tests, So I assume that the scan tool is operating the gauge in a different way to the sender unit, which is not much use for diagnostic purposes. ??

The customer fitted a replacement cluster on my diagnosis and luckily it cured the problem.

H.T.H. Tony.