Coming home yesterday from a 80km+ trip I found this routing directions on the last kilometers (on Leipziger Straße around 142 in Chemnitz approx 3to4 km to go to target):
It is a deviation to a very nearby parallel road for about 200 m and than back to the main road.
So I checked today, what may be the reason and I found, that the alternative I had choosen creates the deviation.
I find, that this alternative is not a real choice which makes any sense whatsoever.
When the direction is just straight, Navigator directs me through (!) a gas station on the right and the left (!!!) side of the road and back to the onward road. If I turn small local roads off, Navigator remains on the road. But I regularly have to use small local roads, because otherwise Navigator calculates substantial detours.
Maybe it's the standard profile for your vehicle. Have you ever tried to change the profile? @chattiewoman has created a proper profile in another forum. Perhaps a similar setting will help you.
I (like to) use "small local roads" as well and this problem I (temporarily) solve by setting speed on them on very low value (22 km/h and 9 km/h in urban areas). l leave all preference settings on 50, other speed settings (especially in urban areas) lower than standard, but not that much. Works good for me, with occasional adventures on narrow roads :-).