添加分账接收方总是提示验证签名失败是什么原因？

<xml>
    <receiver>
        <![CDATA[{"account":"oZlEK4yd4Jv5gcyni5BR2hOO2wBo","relation_type":"USER","type":"PERSONAL_OPENID"}]]>
    </receiver>
    <appid>
        <![CDATA[wx5dd15cfa8429ee97]]>
    </appid>
    <mch_id>
        <![CDATA[1607965846]]>
    </mch_id>
    <nonce_str>
        <![CDATA[NqO3ovTkSdc7nWpuQGyr5AiEsXl80IML]]>
    </nonce_str>
    <sign_type>
        <![CDATA[HMAC-SHA256]]>
    </sign_type>
    <sign>
        <![CDATA[5E2EF73572274238EF4B17D8A2BAF3ED41F7916279A0637513EFCD4DB7FB7DF0]]>
    </sign>
</xml>

https://pay.weixin.qq.com/wiki/doc/api/allocation.php?chapter=27_3&index=4

校验是正确了

但返回总是这样

<xml>
<return_code><![CDATA[SUCCESS]]></return_code>
<result_code><![CDATA[FAIL]]></result_code>
<err_code><![CDATA[SIGN_ERROR]]></err_code>
<err_code_des><![CDATA[验证签名失败]]></err_code_des>
<mch_id><![CDATA[1607965846]]></mch_id>
<appid><![CDATA[wx5dd15cfa8429ee97]]></appid>
<receiver><![CDATA[{"type":"PERSONAL_OPENID","account":"oZlEK4yd4Jv5gcyni5BR2hOO2wBo","relation_type":"USER"}]]></receiver>
<nonce_str><![CDATA[66bcd8661413b613]]></nonce_str>
<sign><![CDATA[46F15678B0DB8BC1D021952C5297727EF292379558453441EF46E1072FD53F1F]]></sign>
</xml>

不知道是哪个地方错了