Hello, and that is completely correct. The entire route is permanently saved within the link.
If you make any changes, you need to send a new link/QR code.
If all users have a Kurviger account, you can also share the route via the cloud, and then everyone will always have the latest version, even if you make changes.
If you open the old link (then presumably a simple Kurviger link), the corresponding (old) route is loaded. What you see as a dashed line is a map overlay. Take a look here.