containers cannot communiate if one is in host network

[What-a-mess]

I was deplying a homelab and trying to get things work with qbittorrent using host network and sonarr using container network (both runs in podman's container). It was working when all containers just started, but then it won't work most of time. Sonarr gives me the error that it cannot connect to qbittorrent.

I tried to run curl -v host.containers.internal:8989 (that's the host and port in sonarr's setting for qbittorrent), sometimes it works, but most of time it will just timeout, and tcpdump shows that the eth0 in sonarr did sent the packet, but the lo in host never received (ping works btw).

I want to know if this is because of my wrong configurations? Or is this just works as intended?

Here are the compose.yaml I'm using for these two services.

version: "2"
services:
  qbittorrent:
    image: superng6/qbittorrent
    container_name: qbittorrent
    environment:
      - PUID=0
      - PGID=0
      - TZ=Asia/Shanghai
      - WEBUI_PORT=8989
      - TL=https://cf.trackerslist.com/best.txt
    volumes:
      - ./config:/config
      - /mnt/allin1/qb-download:/downloads
      - /mnt/allin1/share-data:/share

    network_mode: host
    http_proxy: false
    restart: unless-stopped

services:
  sonarr:
    image: lscr.io/linuxserver/sonarr:latest
    container_name: sonarr
    environment:
      - PUID=0
      - PGID=0
      - TZ=Asia/Shanghai
    volumes:
      - ./sonarr/config:/config
    ports:
      - 9001:8989
    networks:
      brlan0:
    http_proxy: false
    restart: unless-stopped

networks:
  brlan0:
    external: true

[baude]

did you run the two without compose and see if things work ?

[What-a-mess]

I tried to create containers with podman command and nothing goes wrong for past 24h. Thanks for help.

why this happens when using compose?