added handler in case something in the config is changed, it will restart the service

roles/zabbix_agent/handlers/main.yml

@@ -0,0 +1,6 @@
+---
+- name: Restart zabbix-agent2
+  ansible.builtin.systemd:
+    name: zabbix-agent2
+    state: restarted
+    daemon_reload: true

roles/zabbix_agent/tasks/main.yml

@@ -30,6 +30,7 @@
     regexp: '^Server='
     line: "Server={{ zabbix_server }}"
   when: zabbix_state == 'present'
+  notify: Restart zabbix-agent2
 
 - name: Configure Zabbix active server address
   ansible.builtin.lineinfile:
@@ -37,6 +38,7 @@
     regexp: '^ServerActive='
     line: "ServerActive={{ zabbix_server }}"
   when: zabbix_state == 'present'
+  notify: Restart zabbix-agent2
 
 - name: Configure Zabbix agent hostname
   ansible.builtin.lineinfile:
@@ -44,6 +46,7 @@
     regexp: '^Hostname='
     line: "Hostname={{ ansible_hostname }}"
   when: zabbix_state == 'present'
+  notify: Restart zabbix-agent2
 
 - name: Configure Zabbix agent listen IP
   ansible.builtin.lineinfile:
@@ -51,6 +54,7 @@
     regexp: '^#?ListenIP='
     line: "ListenIP=127.0.0.1"
   when: zabbix_state == 'present'
+  notify: Restart zabbix-agent2
 
 - name: Enable and start Zabbix agent2
   ansible.builtin.systemd: