This is what my Garmin showed about 1km into the BB200...
Riding from screen right to left, we have a purple line with black border, an unbanded purple line, and a white arrow telling me to make a u-turn. The spurious white direction arrows were rare after this, but the multiple purple lines came back several times.

The maps are the Talkytoaster free set, all I have done is drop the supplied gpx into the newfiles folder.

Any tips would be welcome.

Andrew

Can't help with the specifics, but on the subject in general... I turn off route guidance for my off road stuff.

Issues like you have there made it just far too annoying to use.

I thought that everything was turned off that could be but I just found the hidden menu in the courses folder and put 'turn guidance' off, that seems to have fixed both problems.

Like Rich says, don't use the guidance. Go to course select it and then you should have a settings option. Go to that and you can select always show. Then go to your maps and make them all disabled. That leaves you with just your location triangle and the line that is the course. It also reduces battery comsumption.

as a guess, the garmin is telling a U-turn since the GPX track has cut a corner so the actual position is "off-track"; the garmin therefore wants to return to that location where they coincide.