Add point to route

I'm away at the moment and have routes set for each day. If I fancy a deviation and add a place of interest I get the option to add to route but it puts it at the end of the route. This means I'd be navigated to my destination then back to that point!
Doubling the route length if the point is near the beginning.
I'd have expected it to navigate to that pony as you got close to it then back to the original route.

not to sure with the nav v , when the route is selected if you zoom in to to the place you want to add and touch the screen at that place does it not ask you to set as waypoint or add to route.

Don't know, I searched for the POI, in this instance Dachau concentration camp and it asked to add to route, but put a load lore miles on the journey even though we were only 5 or so miles away.
My work round is just to navigate to the POI then chose my stored route and navigate to the end. It just picks up from where I am, or maybe not, it did totally miss out the Allianz Arena even though I had waypoints set right by the stadium??? Who knows !