Use correct path when checking if the certificate already exists.

tasks/tls.yml

 ---
-- name: "<{{item | regex_replace('/var/lib/acme/live/(.*)/haproxy', '\\1')}}> Gather Cert stats"
+- name: "<{{ item }}> Gather Cert stats"
   stat:
-    path: "{{ item }}"
+    path: "/var/lib/acme/live/{{ item }}/haproxy"
   register: cert
 
-- name: "<{{item | regex_replace('/var/lib/acme/live/(.*)/haproxy', '\\1')}}> Run acmetool (Make sure your system is accessible from the internet!)"
-  shell: "acmetool want --batch {{item | regex_replace('/var/lib/acme/live/(.*)/haproxy', '\\1') }}"
+- name: "<{{ item }}> Run acmetool (Make sure your system is accessible from the internet!)"
+  shell: "acmetool want --batch {{ item }}"
   register: result
   changed_when: "result.stdout"
   when: not cert.stat.exists