Incorrect IP address of docker container

I use RockyLinux and I have installed Docker for my services. My docker-compose.yml file looks similar like this:

version: "3.9"
 
services:
  service_a:
    container_name: service_a
    build: ./images/service_a
    hostname: service_a
    restart: always    
    environment:
      TZ: 'Europe/Warsaw'
    networks:
      default_network:
        ipv4_address: 172.16.238.20
        aliases:
          - service_a.lan
  
  service_b:
    container_name: 'service_b'
    build: ./images/service_b
    hostname: service_b
    restart: always      
    environment:
      TZ: 'Europe/Warsaw'      
    networks:
      default_network:
        ipv4_address: 172.16.238.21
        aliases:
          - service_b.lan
      
networks:
  default_network:
    driver: bridge    
    ipam:
      driver: default
      config:
        - subnet: 172.16.238.0/24

I have tried to communicate between the above services (let's assume that I connected from service_b to service_a). When I was analysing network trafic on one of container (let's asume that it is service_a) I noticed that all incomming traffic has incorrect ip address (172.16.238.1 instead of 172.16.238.21). I would like to get IP of service_b (172.16.238.21). What can I do to achieve this goal?

Problem solved. The system has been restarted and it works.