E-route numbers in UK

I noticed when turning onto the A1(M) road in the UK that instead of it showing the road’s name which is A1(M) the app showed a turn indication onto E15.

This is the European road network designation. However it is not and has never appeared on any UK signage, doesn't appear on any mapping platform. And thus isn’t at all useful for navigation purposes.

The direction indications shouldn’t show E road numbers in the UK

In addition I have noticed an almost complete absence of road numbers shown in the app in general. Google Maps for example always shows them and shows correctly.

CarPlay on iPhone