TX interrupt problem. Works only with RX_Timeout>0

Ultra-Wideband
,
#1

Hello, im working on transmission and reception with interrup routine. I have a problem with this. One board sends a packet every 100ms(lets name it Master) and then go to Receive state. Another board collects this and send response(Slave).
it is working only if i set (dwt_setrxtimeout(RX_RESP_TO_UUS) with RX_RESP_TO_UUS !=0 (i have TX_SENT ), if it RX_RESP_TO_UUS = 0, i havent TX_SENT interrupt.
I tried to work with example ex_03d_tx_wait_resp_interrupts and switch initialisation in this example with my setup and it has a interrupt also with my setup(once time because of example algorithm).
I use this setup

peripherals_init();
port_set_deca_isr(dwt_isr);
RCC_LSICmd(ENABLE);
  /* Wait till LSI is ready */
  while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET)
  {}
reset_DW1000();
spi_set_rate_low();
if (dwt_initialise(DWT_LOADUCODE) == DWT_ERROR)
{
    lcd_display_str("INIT FAILED");
    while (1)
    { };
}
spi_set_rate_high();
dwt_configure(&config);
dwt_setcallbacks(&tx_conf_cb, &rx_ok_cb, &rx_to_cb, &rx_err_cb);
dwt_setinterrupt(DWT_INT_TFRS | DWT_INT_RFCG |  DWT_INT_RPHE | DWT_INT_RFCE | DWT_INT_RFSL | DWT_INT_SFDT, 1);
dwt_setrxaftertxdelay(TX_TO_RX_DELAY_UUS);
dwt_setrxtimeout(RX_RESP_TO_UUS);      //in my code i only change this, only if RX_RESP_TO_UUS>0 i have TX_Ok interrupts

Master transmit every 100ms with this code
dwt_write32bitreg(SYS_STATUS_ID, SYS_STATUS_RXFCG);
stat_reg = dwt_read32bitreg(SYS_STATUS_ID); //stat_reg=0x00800002
ctrl_reg = dwt_read32bitreg(SYS_CTRL_ID); //ctrl_reg = 0x02;
dwt_writetxdata(beacon_msg.hdr.length, (uint8*)&beacon_msg, 0); /* Zero offset in TX buffer. */
dwt_writetxfctrl(beacon_msg.hdr.length, 0,0);
dwt_starttx(DWT_START_TX_IMMEDIATE);
stat_reg = dwt_read32bitreg(SYS_STATUS_ID);
ctrl_reg = dwt_read32bitreg(SYS_CTRL_ID);

Interrupt is
static void tx_conf_cb(const dwt_cb_data_t *cb_data)
{
sent();
}

Problem is in this that i have interrupt with TX_OK only if RX_RESP_TO_UUS>0. How can i fix this?Also slave see Frames only if RX_RESP_TO_UUS>0, so it seems that there is no any send. Also i cant find a problem.