Переписал всё, сейчас вроде как отрабатывает без ошибок

roles/pleroma_postinstall/templates/pleroma.nginx.j2

@@ -0,0 +1,16 @@
+server {
+    server_name    {{ pleroma_building_domain }};
+
+    listen         80;
+    listen         [::]:80;
+
+    # Uncomment this if you need to use the 'webroot' method with certbot. Make sure
+    # that the directory exists and that it is accessible by the webserver. If you followed
+    # the guide, you already ran 'mkdir -p /var/lib/letsencrypt' to create the folder.
+    # You may need to load this file with the ssl server block commented out, run certbot
+    # to get the certificate, and then uncomment it.
+    #
+    location ~ /\.well-known/acme-challenge {
+        root /var/lib/letsencrypt/;
+    }
+}