isc-dhcp 4.2.5 does not support dhcp-client-id and vendor-class-id?

I have isc-dhcp-4.2.5 server and client installed on two CentOS-7.4 boxes. I know this is quite old distro, but I can't change it for various reasons.

Dhcp server configuration:

option domain-name "mydomain.org";
option domain-name-servers ns1.mydomain.org, ns2.mydomain.org;

default-lease-time 600;
max-lease-time 7200;

log-facility local7;

option space myspace;
option myspace.node-ip code 1 = ip-address;

# Tell the server to return vendor-specific information
option dhcp-parameter-request-list 43;

class "vendor-classes" {
    match option vendor-class-identifier;
}

subclass "vendor-classes" "my-vendor-class-ID" {
    vendor-option-space myspace;
    option myspace.node-ip 10.5.6.7;
}

subnet 10.0.0.0 netmask 255.255.255.0 {
    range 10.0.0.50 10.0.0.60;
    option routers 10.0.0.254;
}

Dhcp client configuration:

interface "veth0" {
    send dhcp-client-identifier "my-client-ID"; 
    send vendor-class-identifier "my-vendor-class-ID";
    send dhcp-lease-time 900;
}

I'm seeing two problems:

1. The client fails to send options dhcp-client-identifier and vendor-class-identifier, tcpdump does not show those
2. The server fails to send Option-43

It's almost that this version does not support dhcp-client-identifier and vendor-class-identifier at all? What am I doing wrong?

PS. Latest ISC-dhcp (ver. 4.4.2) built from https://gitlab.isc.org/isc-projects/dhcp has no these problems.