My car has traffic sign recognition etc. and does everything that the op listed. I also had even stranger behaviour when the NAV SD card was not installed. I keep my NAV card data up to date, so that is not the reason.
Another weird thing I’ve noticed is the limit indication changing to 60 when I go under or over motorway bridges.
They will have to improve this indication before it can ever be used for the active speed limiting we are threatened with.
As Fred said, Waze gets all this right, all the time!