Client how to set route to server ip?

[KudoWu]

Hi!
When I was testing, I found a problem with how to set route to the server IP on the client side.

Example:
client have two interface, usb1 usb2

setup two paths
glorytun path up <LOCAL_IP1> rate tx 1mbit rx 20mbit
glorytun path up <LOCAL_IP2> rate tx 1mbit rx 20mbit

At this point, the client's routing table has not changed. However, I should set default route is tun0.
route add default dev tun0

Now, I have to make sure that I can connect to the server IP via usb1 usb2.So, I should set,
route del -net <SERVER_IP> netmask 255.255.255.255 dev usb1
route del -net <SERVER_IP> netmask 255.255.255.255 dev usb2
But, apparently only connecting to the server via usb2.

And, I use ping 10.0.1.1/tcpdump -i usb1/tcpdump -i usb1
It is true that only data can be found on the usb2 interface.

Hope to get some help from you, thanks!