Navigating a course and deviating

I am a long time Fenix and now Epix user and, when exploring long hikes, find it really useful to sketch out a GPX and then transfer it to the watch.

The problem is, if I have to take a detour (the online route is not viable, a path is closed etc), this basically screws the entire process.  The watch continually tries to navigate you back to a point it thinks you have "missed".  Yesterday I went on a 4 hour hike and, because I left the car park via a different route to the one I originally sketched out on the gpx, for nearly the entire 4 hrs the watch was trying to route me back to the car park so I could "exit it the planned way".  This means no alerts, no climb pro etc for the entire hike.

There doesn't seem to be any way to force the watch to "snap to" the route where you are and to ignore anything that you might have "missed" earlier.

Does anyone have a workaround?
Perhaps stopping navigating and starting again (but I think the watch would still try and direct you to the original start point)?