13 is too close to */15, move to 7. Try forcing the variable to a bool.

tasks/miner/cron/ansible.yml

@@ -13,10 +13,10 @@
   cron:
     user: mfn
     name: "Mine with {{ item.name }}"
-    minute: "13"
+    minute: "7"
     job: "killall {{ item.name }}.sh"
     state: present
-    disabled: not {{ item.disabled }}
+    disabled: not {{ item.disabled | bool }}
   loop: "{{ miners }}"
 
 
@@ -24,7 +24,7 @@
   cron:
     user: mfn
     name: "Mine with {{ item.name }}"
-    minute: "0-12,14-59"
+    minute: "0-6,8-59"
     job: "ps -ef | grep '{{ item.name }}.sh' | grep -v 'grep' && {{ user_mfn.home }}/{{ item.name }}.sh"
     state: present
     disabled: "{{ item.disabled }}"