HarmonyOS 鸿蒙Next应用开启长时任务后退后台几小时后蓝牙自动断开，重连时调用 getPersistentDeviceIds 报错 2900003（蓝牙开关已关闭）

HarmonyOS 鸿蒙Next应用开启长时任务后退后台几小时后蓝牙自动断开，重连时调用 getPersistentDeviceIds 报错 2900003（蓝牙开关已关闭） 【问题描述】：开发的应用使用 backgroundTaskManager 申请长时任务后置于后台运行，经过几个小时（例如从 22:00:07 开始）蓝牙连接会自动断开。在断线重连逻辑中，直接调用 getPersistentDeviceIds 接口获取已配对设备 ID 以进行重连，但该接口返回错误码 {“code”:“2900003”}，错误提示为“蓝牙开关已关闭”。检查手机系统设置，确认蓝牙开关实际处于开启状态。

【问题现象】：

1. 应用退至后台数小时后，蓝牙连接无征兆断开。
2. 断连事件触发自动重连逻辑，但在重连第一步获取持久化设备 ID 时失败。
3. 接口报错内容为 get Persistent Device Ids {“code”:“2900003”}，含义为蓝牙开关关闭。
4. 手动检查手机蓝牙开关为打开状态，错误与实际情况不符。

【版本信息】：

设备：CLS-AL00 6.0.0.130(SP25C00E130R5P6patch01)（API Version 22）

【复现代码】：

private _reconnect() {
    setTimeout(() => {
      SLog.info("auto reconnect")
      if (this.connState === BleState.RECONNECTING) {
        SLog.error("正在重连......")
        return;
      }
      this._updateState(BleState.RECONNECTING);
      this.disconnect();
      try {
        let deviceIds = access.getPersistentDeviceIds();
        SLog.debug('deviceIds: ', deviceIds);
        if (deviceIds != null && deviceIds.length > 0) {
          this.connect(deviceIds[0]);
        }
      } catch (error) {
        SLog.error('get Persistent Device Ids', JSON.stringify(error))
      }
    }, 1000)
  }

/** 连接设备 */
  connect(device: BleDevice | string) {
    this.manager.connect(device, {
      onStartConnect: () => SLog.info("connecting"),
      onConnectSuccess: (bleDevice: BleDevice) => {
        SLog.info("connect success")
        this.currentDevice = bleDevice
        access.addPersistentDeviceId(bleDevice.mDeviceId).catch((err: BusinessError) => {
          SLog.error('add Persistent DeviceId:', JSON.stringify(err));
        });

        this.manager.getBluetoothGattServices(bleDevice, (err, services) => {
          services.forEach((service: ble.GattService) => {

            if (service.serviceUuid.toUpperCase() == UUID.SERVICE_UUID.toUpperCase()) {
              this.serviceUuid = service.serviceUuid;
              SLog.info("Service UUID:", service.serviceUuid);
              SLog.info("Service characteristics count:", service.characteristics.length);

              service.characteristics.forEach((char, index) => {
                SLog.info(`Characteristic ${index} UUID:`, char.characteristicUuid);
                SLog.info(`Characteristic ${index} properties:`, JSON.stringify(char.properties));

                // 检查所有可能的写入属性
                const hasWrite = char?.properties?.write || false;
                const hasWriteNoResponse = char?.properties?.writeNoResponse || false;
                // const hasSignedWrite = char?.properties?.signedWrite || false;

                SLog.info(`Characteristic ${index} hasWrite:`, hasWrite);
                SLog.info(`Characteristic ${index} hasWriteNoResponse:`, hasWriteNoResponse);
                // SLog.info(`Characteristic ${index} hasSignedWrite:`, hasSignedWrite);

                if (char?.properties?.notify && char.characteristicUuid.toLowerCase() == UUID.READ_CHAR.toLowerCase()) {
                  SLog.info("Notify Characteristic UUID:", char.characteristicUuid)
                  this.notify(service.serviceUuid, char.characteristicUuid)
                }

                // 选择第一个支持写入的特征值
                if ((hasWrite || hasWriteNoResponse) &&
                  char.characteristicUuid.toLowerCase() == UUID.WRITE_CHAR.toLowerCase()) {
                  SLog.info("Write Characteristic UUID:", char.characteristicUuid)
                  this.writeCharacteristicUuid = char.characteristicUuid;
                }
              })
            }

          })

          // 打印最终使用的 UUID
          SLog.info("Final Service UUID:", this.serviceUuid);
          SLog.info("Final Write Characteristic UUID:", this.writeCharacteristicUuid);

        })
      },
      onConnectFail: (device, e) => {
        SLog.error("connect fail", e)
        this._updateState(BleState.ERROR)
        this._reconnect()
      },
      onDisConnected: () => {
        SLog.info("disconnect")
        this._updateState(BleState.DISCONNECTED)
        this._reconnect()
      }
    })
  }