I have experienced something really similar. Not a detour, but, well…
In early 2019 (or maybe late 2018), whenever I used google maps and the route took me over on a certain stretch road, it would announce the location of an Auto Zone regardless of bearing on the route.
It was just a straight section of road with no confusing areas that needed any clarification. Yet the navigation voice would announce “In a quarter mile, continue past the Auto Zone” followed by “Continue past the Auto Zone on the right.” (Or left.)
It was so jarring and offensive that I also wanted to stop using Google Maps.