routing problem

Hello,
I have an ubuntu virtual machine connected to a vyos vm, vyos vm is also connected not directly to a webserver vm.

vyos and ubuntu vm are in the same subnet:
Vyos:
192.168.9.216 0.0.0.0 255.255.255.248 U 0 0 0 eth8

vyos and webserver vm are not connected directly:
S>* 0.0.0.0/0 [1/0] via 172.16.1.2, eth12.1011

When i ping from the ubuntu machine to the webserver 192.168.9.218 --> 172.16.1.5 I can see the icmp request and reply through eth12, but the reply never goes to the ubuntu vm trough eth8. In eth8 i can only see the requests coming into vyos.

vyos@vyos:~$ sudo tcpdump -vv -i eth12
tcpdump: WARNING: eth12: no IPv4 address assigned
tcpdump: listening on eth12, link-type EN10MB (Ethernet), capture size 65535 bytes
14:56:49.434664 ARP, Ethernet (len 6), IPv4 (len 4), Request who-has 172.16.1.1 tell 172.16.1.2, length 46
14:56:49.434697 ARP, Ethernet (len 6), IPv4 (len 4), Reply 172.16.1.1 is-at 52:54:00:52:20:a4 (oui Unknown), length 28
14:56:52.177206 IP (tos 0x0, ttl 63, id 26230, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.9.218 > 172.16.1.5: ICMP echo request, id 2910, seq 1, length 64
14:56:52.181942 IP (tos 0x0, ttl 64, id 24332, offset 0, flags [none], proto ICMP (1), length 84)
172.16.1.5 > 192.168.9.218: ICMP echo reply, id 2910, seq 1, length 64
14:56:53.184404 IP (tos 0x0, ttl 63, id 26412, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.9.218 > 172.16.1.5: ICMP echo request, id 2910, seq 2, length 64
14:56:53.188501 IP (tos 0x0, ttl 64, id 24376, offset 0, flags [none], proto ICMP (1), length 84)
172.16.1.5 > 192.168.9.218: ICMP echo reply, id 2910, seq 2, length 64
14:56:54.192236 IP (tos 0x0, ttl 63, id 26643, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.9.218 > 172.16.1.5: ICMP echo request, id 2910, seq 3, length 64

vyos@vyos:~$ sudo tcpdump -vv -i eth8
tcpdump: listening on eth8, link-type EN10MB (Ethernet), capture size 65535 bytes
15:10:08.964670 IP (tos 0x0, ttl 64, id 30564, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.9.218 > 172.16.1.5: ICMP echo request, id 2915, seq 1, length 64
15:10:09.972121 IP (tos 0x0, ttl 64, id 30786, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.9.218 > 172.16.1.5: ICMP echo request, id 2915, seq 2, length 64
15:10:10.980185 IP (tos 0x0, ttl 64, id 30908, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.9.218 > 172.16.1.5: ICMP echo request, id 2915, seq 3, length 64
15:10:11.988217 IP (tos 0x0, ttl 64, id 31087, offset 0, flags [DF], proto ICMP (1), length 84)
192.168.9.218 > 172.16.1.5: ICMP echo request, id 2915, seq 4, length 64

This is the routing table in the ubuntu machine:
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 192.168.9.217 0.0.0.0 UG 0 0 0 eth1
192.168.9.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0

192.168.9.217 is vyos ip in eth8.

Could you help me?
Thanks and BR/
Cristina.