Welcome to Kurviger and thanks for the detailed report!
(we need such detailed reports to improve the app / website)
There are off route warning and tone options in voice guidance settings.
Listening to any of these, there is voice / audio signal of being off route.
This is a classic routing issue (not app).
Unfortunately Kurviger routing does not respect the user location heading,
so such routing problems (routes calculated behind the user) can happen.
Kurviger server insists to calculate routes in the opposite direction of user.
It is discussed here:
Also mentioned in your linked topic: