Android SSL HttpUrlConnection 提示 hostname "ip" was not verified

[Vindroid]

局域网内服务器使用自签名证书 server.csr Certificate Request:

Data:
    Version: 0 (0x0)
    Subject: C=CN, ST=JiangSu, L=xxx, O=xxx, OU=xxx, CN=10.89.33.52
    Subject Public Key Info:
        Public Key Algorithm: rsaEncryption
            Public-Key: (2048 bit)
            Modulus:
                *****
            Exponent: 65537 (0x10001)
    Attributes:
        unstructuredName         :unable to print attribute
    Requested Extensions:
        X509v3 Basic Constraints:
            CA:FALSE
        X509v3 Key Usage:
            Digital Signature, Non Repudiation, Key Encipherment
        X509v3 Subject Alternative Name:
            DNS:10.89.33.52
Signature Algorithm: sha256WithRSAEncryption
     *****

在 android 下通过 httpurlconnection 连接会报 hostname "10.89.33.52" was not verified ，而使用域名，再在 etc/hosts 中新增条目，却可以正常访问，有人知道这是什么情况么？

设置的 ip 均为保留地址， server.crt 证书也导入到 android 中，浏览器能正常访问，也显示为认证通过。