PC-BLE-Driver - Some advertisement lengths faulty/forbidden? [sdk5 v14.0.0]

I have strange problem using pc-ble-driver on nrf52 with heart_rate_monitor example.
When I set advertisement data to be 16 bytes long, two of our testing phones cannont see proper advertisement data (iPhone 6 iOS 10.2.1 and Sony Xperia Z5 Android 7.1.1)
It should me seen as connectable with 11 bytes of manufacturer data, but it's seen as unconnectable and without manufacturer data at all.
When I change manufacturer data to be one byte shorter, then everything is ok, one or two bytes more and it doesn't work, 6 bytes more and it start working again.

This is (not working) my setup:

    data_buffer[index++] = 0x02;
    data_buffer[index++] = BLE_GAP_AD_TYPE_FLAGS; // 0x01

    data_buffer[index++] = 0x0C;
    data_buffer[index++] = 0xFF;
    data_buffer[index++] = 0x88;
    data_buffer[index++] = 0x44;
    data_buffer[index++] = 0x55;
    data_buffer[index++] = 0x34;
    data_buffer[index++] = 0x03;
    data_buffer[index++] = 0x11;
    data_buffer[index++] = 0x22;
    data_buffer[index++] = 0x33;
    data_buffer[index++] = 0x44;
    data_buffer[index++] = 0x55;
    data_buffer[index++] = 0x66;

    uint8_t sr_data[9];
    sr_data[0] = 0x08;
    sr_data[1] = 0x09;
    sr_data[2] = 0x43;
    sr_data[3] = 0x6F;
    sr_data[4] = 0x6E;
    sr_data[5] = 0x6E;
    sr_data[6] = 0x65;
    sr_data[7] = 0x63;
    sr_data[8] = 0x74;
    error_code = sd_ble_gap_adv_data_set(m_adapter, data_buffer, index, sr_data, 0x09);

Thanks for any help :)