Tcpdump issue when building firmware for Mikrotik mAP Lite

I'm trying to build firmware for mAP Lite.
I need tcpdump and python3-paho-mqtt there.

I tried to use ready [firmware](http://downloads.openwrt.org/releases/18.06.4/targets/ar71xx/mikrotik/openwrt-18.06.4-ar71xx-mikrotik-rb-nor-flash-16M-initramfs-kernel. bin).
On it, tcpdump works fine, but there is no paho-mqtt.

If I try to build the firmware from the latest sources (main branch from GitHub), then there is paho-mqtt, but tcpdump does not work correctly, i.e. when i run

iw phy phy0 interface add moni0 type monitor
ifconfig moni0 up
tcpdump -tt -y ieee802_11_radio -i moni0 -e -s 0 -l type mgt subtype probe-req

I get nothing, tcpdump is silent.
I used make menuconfig and chose

  • Target System (Atheros AR7xxx/AR9xxx)
  • Subtarget (Mikrotik devices with NAND/NOR flash)
  • Target Profile (MikroTik RouterBoard (16 MB SPI NOR))
  • plus tcpdump, python3-light and python3-paho-mqtt

What am I doing wrong?
Maybe I forgot some packages or something else?
Is it possible to solve this problem at all or not?