The vehicle speed is detected from the wheel sensors and fed through the ABS controller. Is there a check engine light? If so, what is the code?

Check the speed sensors on each front wheel. Were the sensors or their wires damaged or disconnected when the axles were replaced? Or if the wheel assembly was not reinstalled correctly, the required clearance between the sensor and the wheel may not be met (gap or space may be too large for the sensor to pick up magnetic pulses from the pulse wheel, that cogged or gear looking disk on the back of the hub).

Jack up the front end and wiggle each wheel. Does either wheel feel loose? Check each axle nut to make sure it is present and at the specificed torque. If the nut is loose or missing, the clearance between the sensor and the wheel will not meet spec.

It is not necessary to disconnect the wheel sensors when you replace the axle, but I seem to recall that VADIS instructs you to do so. If this was done, perhaps its as simple as having overlooked reinstalling the sensors.