A6 C8 drive system fault - intermittent

Hi - my A6 C8 2.0 diesel has started throwing a “Drive system fault: contact workshop” error - it’s happened around four times in the last week. First three when using cruise control - which is knocked off and can’t be used once the error appears. The latest time error appeared when in normal driving.

After stopping and restarting the error clears. Doesn’t appear on every drive - sometimes more than 60 miles in. Stop start and intelligent coasting all appear normal. In every other respect the car seems to be driving normally.

i’m away from home for the next few days with the car and will take to main dealer when i return. Thought I would see if anyone had any ideas/advice?

Thanks