As you can see:
1. The shaping or via points are offset from the road. This suggests that the original route was created in a different or earlier map, even possibly in some other make of software.
2. BaseCamp has done its best to join the offset points up AND to take you along the yellow / orange coloured roads, past Jaca.
3. The black line of the route travels in two directions. You can see this in the direction arrow head pointers. The reason why might be as simple as the route backtracks on itself deliberately or, (maybe more likely) one or more of the shaping points have been created in the wrong order, forcing a return journey.
A forced recalculation of the route might force the black line onto the roads properly. Or some more work might need to be done. Either way, it’s definitely not Garmin’s BaseCamps fault; it has done its best.