The provided GPX contains 5 routes in Garmin format, probably created with basecamp.
Kurviger can not handle this format properly and always takes the 1st route found in GPX.
You can
extract each of the desired route to a separate GPX (e.g. With gpxshaping.de)
Ich you use gpxshaping.de, you do not need to save GPX files, but can open a shown route in Kurviger directly
Do following for the routes “xxx Leg1 -SHP”, “xxx Leg2 -SHP”, “P-Town loop option”: