I follow the README instruction to build liboqs and openssl in a Ubuntu 18.04.
After that, I want to do a quick test with build openssl s_server / s_client with instruction in README:

First, I created a self-signed certificate 2 commands:

1. $ apps/openssl ecparam -name secp384r1 -genkey -param_enc explicit -out private-key.pem
2. $ apps/openssl req -new -x509 -key private-key.pem -out server-cert.pem -days 365 -config apps/openssl.cnf

Now I try TLS1.3 connection with openssl s_server / s_client:

1. in first terminal, start server:

$ apps/openssl s_server -cert server-cert.pem -key private-key.pem -www -tls1_3
Using default temp DH parameters
ACCEPT

2. in second terminal, start client:

$ apps/openssl s_client -groups kyber512 -CAfile server-cert.pem
CONNECTED(00000003)
write:errno=0
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 1111 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---

3. now back to server terminal, server core dumped

Using default temp DH parameters
ACCEPT
Segmentation fault (core dumped)

4. interestingly, if I specify non-443 port number in s_server command, I can get core dump when starting server

$ sudo apps/openssl s_server -cert server-cert.pem -key private-key.pem -www -tls1_3 -accept 4443
Using default temp DH parameters
ACCEPT
Segmentation fault

Do I have some misconfiguration ? or running command with wrong parameters ?