So I understand that the App has its own routing algorithm which is for last resort use only. Generally the App uses the Waze routing server to determine a route / destination. I have a vague recollection that LiveMap uses a different routing server / data. I was wondering if an issue needs raising in the Navigation Forum or if this is just ‘normal’.
The issue was raised by Simon when he was navigating to 169 Spencefield Lane. When I use the LiveMap it drops the pin in the expected location and also routes to the same location. Using the App it routes you off the correct road and into a side street that is near but not the closest segment :?
The easy fix would be to shorten Spencefield Drive and add House Numbers along Spencefield Lane. I have not done this yet, to not confuse the issue, as this seems a failure in routing to the nearest point.
Routing experts to the front of the queue.
I’m getting the same result on WME, Live Map, Google Maps and in the app, taking me to a location outside #169, if the house numbering is as might be expected. I can see #173 on Streetview, two houses to the south, but both 171 and 169 are not displaying house numbers that I can see on the Streetview images.
(I always thought that was a legal requirement, enforced by Royal Mail refusing to deliver post to houses not showing a house number, but that may be folklore, or privatisation having done away with such standards! Lack of visible house numbers is becoming endemic 
)
I can’t replicate a destination location on Spencefield Dr, so perhaps something has changed even without you doing anything :?
Still running the 3.x Android app here, and asking for a route to 169 Spencefield Lane from my current location in Maidenhead, I get a result identical to the screengrab above - the destination flag is placed at the correct location, but the route highlight ends on Spencefield Drive instead.
If I then tap-hold on the same point along Spencefield Lane where 169 is located, and ask for a route to that location, the app now gives me a route directly there.
Asking for routes to other nearby numbered addressed on Spencefield Lane (e.g. number 171) also returns a route which ends on the Drive instead.