Software update for speed sign recognition?

[geoffb]

I recently traded in my 73 plate SE for 75 plate Extended range trophy. The traffic sign recognition worked tolerable well on the old SE. However on the 75 plate it seems to randomly freeze. It seems to recognise the first sign and then freezes. I can make the same journey on another day and it picks up every limit change. I have tried rebooting the infotainment system but this makes no difference. I also make sure everything is fully booted before setting off.

Is this a known software issue? I haven't been able to find a relevant thread on the subject Infotainment is R32 if that's relevant)