[Help] two instances of WireGuard cannot access each other

jerry_me

Instance 1:

[Interface]
PrivateKey = *****
ListenPort = 30001
PostUp = ip addr add 2404:f4c0:f4c0::1/48 dev %i peer 2404:f4c0:4fc0::2/48
Table = off

[Peer]
PublicKey = *****
Endpoint = 192.168.0.104:30001
AllowedIPs = 0.0.0.0/0, ::0/0

Instance 2:

[Interface]
PrivateKey = *****
ListenPort = 30001
PostUp = ip addr add 2404:f4c0:f4c0::2/48 dev %i peer 2404:f4c0:f4c0::1/48
Table = off

[Peer]
PublicKey = *****
Endpoint = 192.168.0.105:30001
AllowedIPs = 0.0.0.0/0, ::0/0

Execute the command in Instance 1:

root@localhost:~# ping -I internal0 2404:f4c0:f4c0::2
PING 2404:f4c0:f4c0::2(2404:f4c0:f4c0::2) from 2404:f4c0:f4c0::1 internal0: 56 data bytes
64 bytes from 2404:f4c0:f4c0::2: icmp_seq=1 ttl=64 time=0.472 ms
64 bytes from 2404:f4c0:f4c0::2: icmp_seq=2 ttl=64 time=0.838 ms
64 bytes from 2404:f4c0:f4c0::2: icmp_seq=3 ttl=64 time=0.699 ms

Execute the command in Instance 2:

root@localhost:~# ping -I internal0 2404:f4c0:f4c0::1
PING 2404:f4c0:f4c0::1(2404:f4c0:f4c0::1) from 2404:f4c0:f4c0::2 internal0: 56 data bytes
^C
--- 2404:f4c0:f4c0::1 ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 80ms

They are both on the same system (Debian 10) and both are fresh installations.

I don't know what I did wrong?