app微信支付签名失败

后端使用的是微信支付apiv3

updateNow() {     
                let _this = this;  
                appPlaceAnOrder(obj).then((res)=>{  
                    let objData = res.data  
                    let orderInfox = {  
                      "appId": objData.appid, // 应用ID（AppID）objData.appid  
                      "noncestr": objData.noncestr, // 随机字符串  
                      "package": objData.package,    // 固定值  objData.package  
                      "partnerid": objData.partnerid, // 商户号（PartnerID）  objData.partnerid  
                      "prepayid": objData.prepayid,  // 预支付交易会话ID  
                      "timestamp": objData.timestamp, // 时间戳（单位：秒）  Number(timestamp)  
                      "sign": objData.sign, // 签名  
                    };  
                    uni.requestPayment({  
                        "provider": "wxpay",  //固定值为"wxpay"  
                        "orderInfo": JSON.stringify(orderInfox),  
                        "timeStamp": JSON.stringify(objData.timestamp),  
                        "nonceStr": objData.noncestr,  
                        "package": objData.package,  
                        "signType": "RSA",  
                        "paySign": objData.sign,  
                        success: function (res) {  
                            var rawdata = JSON.parse(res.rawdata);  
                            console.log("支付成功");  
                        },  
                        fail: function (err) {  
                            console.log('支付失败:' + JSON.stringify(err));  
                        }  
                    });  
                })  
            },

前端代码是这样的。
接口返回：

"package": "Sign=WXPay",
"paySign": "39ee946c1d50ac5424**",
"appid": "wxfd325",
"sign": "UGO0mSbSBLrR4j4BBDz0/YZjwlo+fzhRA1H6AKF5Xb2dg1bbtov2xe5U1+cb1ql3B1j4YOwnHva+vOFk6Io4Uw9lqdhXIwQfl7ka/dNpLBLPBeDEsa9WCVFFpMdQjcOMY1YClfnubLUfUGCgeinb+MRdgJ5P42PcYp2bxIUm6VKmJwDEQ/P6HCpgSPDwU/zXG1KPj7uACMWKnNQ9YzoVE2uOXqNvgpNUL5Fh7iU+bPwN1PUQMpZ9h0wvBi7n4jc33ycGs0rwXrdzHCyPlnV7DrjnjXGolDsBBJ1uAS/k3v5c+NKBEXYkY4AczQ3v3TJcnk5sUPTNOKCWdSqBXK2xvw==",
"partnerid": "15812",
"prepayid": "wx25143828099744f6059**",
"noncestr": "eKJvggxtrGAvB4mshGy7JgZGG5pQmLlS",
"timestamp": "1714027106"

现象：第一次调起支付成功，后面的都报错：
支付失败:{"errMsg":"requestPayment:fail [payment微信:-1]General errors","errCode":-100,"code":-100}

求指教哪里有问题。卡了5天了。