DHCP doesn't distribute default route to fixed leases

[rhartmannh]

We are running OPNSense 19.7.4 with DHCP4 activated on the LAN interface. DHCP distributes fixed IP addresses to many Linux VMs, along with a lot of static routes that have been defined in system->routes. All of the Linux VMs receive the static routes properly, but they don't get a default route. So after a VM reboot it looks like this:

root@onlyofficeprod:/home/roland# ip route
10.8.1.0/24 via 192.168.0.226 dev ens3
100.70.4.39 via 192.168.0.227 dev ens3
192.168.0.0/24 dev ens3 proto kernel scope link src 192.168.0.174
192.168.3.1 via 192.168.0.26 dev ens3

The default route has to be added manually. In contrast to the described situation with fixed leases, clients with dynamic leases receive their default route properly.

Does anyone have an idea why that happens and how it can be fixed?

Thanks!
Roland