DHCP Kea High Availability over TLS doesn't work

I have installed 2 Kea 2.0.1 Servers in Debian 10 Buster virtual machine in Virtual Box 6.1.26 r145957 (Qt5.6.2) and also in VMware Workstation Player 16.1.2 build-17966106.The high availability without TLS works fine and I have been referred to kea admin reference manual for kea-dhcp4 and kea-ca(controlagent) configurations(https://kea.readthedocs.io/en/kea-2.0.1/arm/intro.html).

HA Logs without TLS

When I try to configure it with TLS it gives the following TLS handshake error.

2022-02-07 10:38:22.970 DEBUG [kea-ctrl-agent.http/4703.140102598186880] HTTP_CONNECTION_HANDSHAKE_START start TLS handshake with 192.168.0.20 with timeout 10 2022-02-07 10:38:23.972 INFO [kea-ctrl-agent.http/4703.140102598186880] HTTP_CONNECTION_HANDSHAKE_FAILED TLS handshake with 192.168.0.20 failed with http request 2022-02-07 10:38:23.972 DEBUG [kea-ctrl-agent.http/4703.140102598186880] HTTP_CONNECTION_STOP stopping HTTP connection from 192.168.0.20

In order to configure tls connection, I have created a certification authority with self signed certificate and a bind9 DNS Server. Regarding the creation of TLS certificates with subject alternative names set to dns name and ip address, I have been referred to /kea-2.0.1/src/lib/asiolink/testutils/ca/doc.txt.

  (Create CA self signed certificate)
$sudo openssl genrsa -aes128 -out kea-ca.key 4096
$sudo openssl req -new -x509 -days 3650 -key kea-ca.key -out kea-ca.crt -extensions v3_ca -config server-conf.cnf


  (Kea server certificate)
$sudo openssl genrsa -aes128 -out kea-server-aes.key 2048
$sudo openssl pkcs8 -in kea-server-aes.key -out kea-server.key -nocrypt
$sudo rm kea-server-aes.key (server private key must be unencrypted)
$sudo openssl req -new -key kea-server.key -out kea-server-addr.csr -config server-addr-conf.cnf
$sudo  openssl x509 -req -days 3650 -in kea-server-addr.csr -CA kea-ca.crt -CAkey kea-ca.key -set_serial 30 -out kea-server-addr.crt -extfile ext-addr-conf.cnf -sha256

 (Use c_rehash or openssl rehash to create hashes)

$sudo openssl rehash .

To troubleshoot I have tried the following:

1. Capturing data packets with wireshark (enter image description here)- After sending a heartbeat message to synchronize with the other peer, something goes wrong and the tcp connection ends immediately. wireshark capture
2. Sending a curl POST to kea control agent works successfully. http response
3. Testing kea certificates with openssl verify tool as described in openssl verify- everything seems to be ok. openssl verify
4. Troubleshooting with tls connection with openssl s_client -showcerts.

Because the error output isn't helping much, I wanted to ask if anyone has any experience regarding this issue or comparable problems.