Extra DNS entries in the Linux routing table

I have a Linux machine Ubuntu 22.04 with two interfaces that I called bond0 and bond1. This machine has IP 10.242.87.123 and the following name servers:

nameserver 161.26.0.7
nameserver 161.26.0.8

This server is part of a Patroni/PostgreSQL cluster and we changed the neplan to let it talk with the other two machines of the same cluster (10.242.23.122 and 10.242.23.126). Here the neplan:

network:
    ethernets:
        ens3:
            dhcp4: true
            match:
                macaddress: 02:00:07:3c:53:e3
            set-name: bond0
        ens4:
            dhcp4: true
            match:
                macaddress: 02:00:09:3c:53:e3
            set-name: bond1
            routes: 
            - to: 10.242.23.122/32
              via: 10.242.87.1 
            - to: 10.242.151.126/32
              via: 10.242.87.1 
    version: 2

we did the same on other Linux Ubuntu 22 and no issues. The problem is that the routing table of this machine has DNS entries like these:

161.26.0.6      0.0.0.0         255.255.255.255 UH    100    0        0 bond1
161.26.0.6      10.242.151.1    255.255.255.255 UGH   100    0        0 bond0
161.26.0.7      0.0.0.0         255.255.255.255 UH    100    0        0 bond1
161.26.0.7      10.242.151.1    255.255.255.255 UGH   100    0        0 bond0
161.26.0.8      0.0.0.0         255.255.255.255 UH    100    0        0 bond1
161.26.0.8      10.242.151.1    255.255.255.255 UGH   100    0        0 bond0

if I remove them with the command:

route del -net 161.26.0.6 netmask 255.255.255.255 dev bond1
route del -net 161.26.0.7 netmask 255.255.255.255 dev bond1
route del -net 161.26.0.8 netmask 255.255.255.255 dev bond1

I am able to ping an external server using the DNS name (before the DNS removal, it could not be reached). The problem is that a background process add them back again. The lucky part is that this time the faulty entries are added in this way:

161.26.0.6      10.242.151.1    255.255.255.255 UGH   100    0        0 bond0
161.26.0.6      0.0.0.0         255.255.255.255 UH    100    0        0 bond1
161.26.0.7      10.242.151.1    255.255.255.255 UGH   100    0        0 bond0
161.26.0.7      0.0.0.0         255.255.255.255 UH    100    0        0 bond1
161.26.0.8      10.242.151.1    255.255.255.255 UGH   100    0        0 bond0
161.26.0.8      0.0.0.0         255.255.255.255 UH    100    0        0 bond1

so it works because probably the 0.0.0.0 entries are after the one with real gateway. My questions are:

1. Why I didn't have the same issues on other Ubuntu 22 machines of other clusters
2. What is the background process that add these extra entries?
3. Could be my netplan configuration file the root cause of the issue?