How to identify the reason behind certificate unknown error - ssl

Question

I'm using jetty v9.4.9. I want to authenticate the requests using client certificate. I have configured keystore file in 'jetty-base\etc'. I'm using self-signed certificates in both server and client.
I have a server certificate and root certificate. I have used OpenSSL to generate keystore file.
From https://www.eclipse.org/jetty/documentation/9.4.x/configuring-ssl.html,
Generating pkcs12 file:
$ cat example.crt intermediate.crt [intermediate2.crt] ... rootCA.crt > cert-chain.txt
$ openssl pkcs12 -export -inkey example.key -in cert-chain.txt -out example.pkcs12
Loading keystore file:
$ keytool -importkeystore -srckeystore jetty.pkcs12 -srcstoretype PKCS12 -destkeystore keystore
Using above methods, I have generatd 'new_keystore' file. I have configured the newely generated keystore file in jetty-base\start.d\ssl.ini as
jetty.sslContext.keyStorePath=etc\new_keystore
jetty.sslContext.trustStorePath=etc\new_keystore
Now I'm sending request using cURL in Windows
Request:
curl -v --cacert root.crt --key client.key --cert client.crt https://localhost:8443
This results in unknown certificate error
CApath: none
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Request CERT (13):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Certificate (11):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS handshake, CERT verify (15):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS alert, certificate unknown (558):
* error:14094416:SSL routines:ssl3_read_bytes:sslv3 alert certificate unknown
* Closing connection 0
curl: (35) error:14094416:SSL routines:ssl3_read_bytes:sslv3 alert certificate unknown
In jetty, how to identify the reason behind the unknown certificate error? Can it be configured to displayed on log file? How to debug and fix it?