S120 scanning can not be sustained

[YeLun]

Hi,

There are two advertise nodes, only broadcast (one packet/s) . The S120 star scan. At the beginning everything is OK，but after a while, maybe 3-5 minutes, only one advertise node can be discovered. Then, after an other 3-5 minutes, the scan return to normal.And this appearance happened periodically, seem there some buffer not be cleaned, or need reset.

For find out what the reason, 1,Already use packet sniffer to test and verify at the same time. 2,Only the most basic codes stay in program.

=========================here the codes ===================SDK 6.1================

SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, false);
err_code = softdevice_ble_evt_handler_set(ble_evt_dispatch);
APP_ERROR_CHECK(err_code);
err_code = softdevice_sys_evt_handler_set(sys_evt_dispatch);
APP_ERROR_CHECK(err_code);

    m_scan_param.active       = 0;            // Active scanning set.
    m_scan_param.selective    = 0;            // Selective scanning not set.
    m_scan_param.interval     = 0x00A0;     // Scan interval.
    m_scan_param.window       = 0x00A0;   // Scan window.
    m_scan_param.p_whitelist  = NULL;         // No whitelist provided.
    m_scan_param.timeout      = 0x0000;       // No timeout.

    err_code = sd_ble_gap_scan_start(&m_scan_param);
    APP_ERROR_CHECK(err_code);