Getting SSLHandshakeException (Handshake failed) when calling SSLSocket#getInputStream

Question

I'm testing a SSLSocket connection for a server running as IntentService I'm running on Android app. For that, I'm using PacketSender to send a SSL packet with data, where it was working when using Socket instead of SSLSocket.

When tring to receive data from PacketSender, the app manages to accept the connection, but throws an Exception (see below) when trying to call getInputStream:

Caused by: javax.net.ssl.SSLProtocolException: SSL handshake aborted: ssl=0xb967c838: Failure in SSL library, usually a protocol error
error:100b60c1:SSL routines:ssl3_get_client_hello:NO_SHARED_CIPHER (external/boringssl/src/ssl/s3_srvr.c:1085 0xac4e759f:0x00000000)
at com.android.org.conscrypt.NativeCrypto.SSL_do_handshake(Native Method)
at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:324)
... 7 more

I followed this answer to try switching from plain Socket to SSLSocket.

EDIT: Tried implementing a self-signed certificate for the server app, but the error is persists.

private SSLContext createSSLContext(){
    try{
        byte[] der = SERVER_CERT.getBytes();
        ByteArrayInputStream derInputStream = new ByteArrayInputStream(der);
        CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
        X509Certificate cert = (X509Certificate) certificateFactory.generateCertificate(derInputStream);
        String alias = cert.getSubjectX500Principal().getName();

        // Create keystore and add to ssl context
        KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
        trustStore.load(null);
        trustStore.setCertificateEntry(alias, cert);

        KeyManagerFactory kmf = KeyManagerFactory.getInstance("X509");
        kmf.init(trustStore, null);
        KeyManager[] keyManagers = kmf.getKeyManagers();

        TrustManagerFactory tmf = TrustManagerFactory.getInstance("X509");
        tmf.init(trustStore);
        TrustManager[] trustManagers = tmf.getTrustManagers();

        SSLContext sslContext = SSLContext.getInstance("TLSv1.1");
        sslContext.init(keyManagers, trustManagers, null);

        return sslContext;
    } catch (Exception ex){
        ex.printStackTrace();
    }

    return null;
}