When configuring firewall rules for services in private networks, you must correctly set up the rules required for DHCP, which provides services with their private IP address. If this is not configured, the service may lose its IP address after the lease expires, which can cause NAT issues and make the service inaccessible from the internet.
These settings are required if you have allow rules configured for services added to private networks.
If rules are configured for both inbound and outbound traffic, you must apply both configurations.
If you have rules created only for inbound traffic, you need to allow inbound traffic to port 68/UDP from the gateway IP address of the private network where the service is located.
Example configuration:

Replace 192.168.0.1 with the gateway address of your private network, or allow the entire private subnet (in this example 192.168.0.0/24) or any addresses (0.0.0.0/0).
If services from different private networks with different gateway addresses are added to the same firewall group, you must create an allow rule for each gateway in the same way.
If rules are created only for outbound traffic, you need to allow outbound traffic to address 255.255.255.255 on port 67/UDP.
Example configuration:

Instead of 255.255.255.255, you can also specify 0.0.0.0/0 to allow all addresses.