Turn around alerts all the time

Hello

I set the "turn around alert" to 1 km so that when I'm following a course, and I took the wrong turn, I would get an alert. Yesterday I rode my bike without following a course and still I get alerts all the time, each km as I set it at that distance. I changed it to 10 km but again I got them every 10 km. So that works fine, but I want it only when following courses.

How can I do that?

Thanks!