This is likely an Open Street Map issue, however I can't figure it out. Something seems wrong on US 101 making it less routeable, and the EA station in Eureka not usually chosen even when better than alternatives.
By adding three guide points, the route will work.
Suggestion: make some sort of diagnostic output from the router to aid in debug of similar issues. Perhaps if guide points have a debug checkbox, and if checked a text dump of router decisions around that guide point is made? Or set some sort of flag?