Our S5 has suddenly started misbehaving with regards to speed sign recognition.
I have the warning turned on, because of the large amount of 20Mph speed limit restrictions in Wales.
Last week we had been travelling through a 20Mph limit and it was correctly showing the 20Mph symbol in the drivers cluster.
We turned into the super market and did our shopping, on returning down the same road ( 20Mph ) it failed to retain in the memory, the last know speed sign.
So as we travelled through the restriction, it was displaying a red circle

️ ( no number provided ) and just three horizontally spaced, black dashes in the centre.
Today we where travelling through a 60Mph limit, but it displayed the same red circle with the black dashes, no number present.
We then entered a 20Mph limit and it correctly displayed the correct 20 sign.
Then I made a right turn off the main road, into a 20 Mph road.
No sign present at this point, but the display changed back to the red circle again with no numbers present ??.
It never displays the figure 60 or 70 anymore either, just the same red circle with three black dashes ????.