HttpsURLConnection, SSLPeerUnverifiedException happens when access to IP Address

Question

Following exception happens when HttpsURLConnection tries to connect to a server using IP address:

source

        val is : InputStream
        var tmf: TrustManagerFactory? = null

        try {
            is = mContext.resources.assets.open("cacert.crt")
            val cf = CertificateFactory.getInstance("X.509")
            val caCert = cf.generateCertificate(`is`) as X509Certificate

            // CA certificate is used to authenticate server
            val caKs = KeyStore.getInstance(KeyStore.getDefaultType())
            caKs.load(null, null)
            caKs.setCertificateEntry("ca", caCert)
            tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm())
            tmf!!.init(caKs)

        } catch (e: Exception) {
            e.printStackTrace()
        }

        // POST body
        val body = mContext.getString(R.string.post_json, mOnePass)

        val url_str = "192.168.10.1/app_auth.html"

        val outputStream: OutputStream? = null
        var inputStream: InputStream? = null
        val ps: PrintStream? = null

        var connection: HttpsURLConnection? = null
        try {
            // Not used for safety
//            val hostnameVerifier = HostnameVerifier { hostname, session -> true }

            val url = URL(url_str)
            connection = url.openConnection() as HttpsURLConnection
            connection.requestMethod = "POST"
//            connection.hostnameVerifier = hostnameVerifier
            connection.connectTimeout = 30000
            connection.readTimeout = 30000
            // set trustManager from crt file
            connection.sslSocketFactory = RNSSLSocketFactory(null, tmf!!.trustManagers)

            // Header
            connection.setRequestProperty("Content-Length", body.toByteArray(charset("UTF-8")).size.toString())
            connection.setRequestProperty("Content-Type", "application/json")
            connection.setRequestProperty("app-key", mOnePass)

            connection.doOutput = true
            connection.doInput = true

            // POST
            val ops = connection.outputStream       // Exception
            val printStream = PrintStream(ops)
            printStream.print(body)
            printStream.flush()
            printStream.close()

.
.
.

error

 javax.net.ssl.SSLPeerUnverifiedException: Hostname 192.168.10.3 not verified:
     certificate: sha1/Zh36HM6MnD49n1NVQ26ZX8BcmRA=
     DN: CN=test,OU=aa,O=bb,L=Shinjuku,ST=Tokyo,C=JP
     subjectAltNames: []

I saw an article that it is necessary to match the CN of the certificate with the IP address, but the IP address of the server to connect to is subject to change, and it is difficult to set the CN of the certificate to the CN.

Thanks for the help.