Hi,
when flying the A320 v2 I've had the same problem occur twice in exactly the same place. The problem is that, although the flight controls remain active, all the MCDU functions, flight displays and autopilot lock. The problem appears to be reproducable. Flying from KLAX to KLAS, when I reach the MILSEN waypoint the problem occurs. Attached is a screenshot of the PFDs and the LittleNavMap flightpath trace. The current flight (slightly right of the flightplan) is showing a 4000' difference to the cockpit after I descended manually. The previous flight (branching to the right and ending abruptly) is from the previous flight where I tried to reset the cockpit by turning off the engine generators and the batteries. This resulted in a CTD. On both flights I had used the Direct function under instruction from ATC but not to the MILSEN waypoint.
On the first flight I was using the MSFS realtime weather, on the second I was using historic weather (for the same date and time as the first (2240z depature from KLAX)) from REX Weatherforce. On both flights I was using BeyondATC for ATC and AI traffic.
This seems to have been reported elsewhere but without any resolution or indication that it's under investigation.