I noticed major issues with the voice directions on my Lumia 650 today, which has previously been great even over long journeys (last used about 2 months ago).
Today there were two occasions' where the voice directions simply didn't make sense, firstly telling me to keep left on a dual carriage way (UK) when it meant to keep right (the on-screen map is correct, and the direction route is correct, its just the voice command which is incorrect). Then later down the same road it tells me to "turn right now" despite there being no right turn and the on screen map showing that it should have said "keep left, then take the fourth exit at the roundabout".
The voice command did tell me to take the fourth exit at the roundabout eventually, but only after I had kept left, not turned right as it had instructed.
Frankly this is just unsafe. Voice directions shouldn't contradict what the on-screen map is showing. I've decided not to use the maps app until this gets sorted, as it left me completely confused as to where I was supposed to be driving, and I had to spend far too much time analysing the on screen map than is safe for me to do IMO.