VIP created with Route domain had some issues

We have some VIPs created using Route Domain 1 however we were not able to reach to any of the VIPs. we have a default route using a default route domain, when I added a default route for RD-1, all the VIPs created with RD 1 started responding but the strange thing is that when I removed the route for RD-1, still those VIPs are reachable. I also tried using VLAN tunnel but reomved VLAN tunnel as well still VIPs are reachable for RD-1. What could be the reason that it was not working before and even after removing the route it's working? will it be any problem in future if failover happens?