common_timezone variable undefined.

I tried running the playbook, but I get this error:

TASK [common : timezone - configure /etc/timezone] *****************************
fatal: [default]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'common_timezone' is undefined\n\nThe error appears to have been in '/Users/mike/Development/HomelabOS/roles/common/tasks/main.yml': line 36, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: timezone - configure /etc/timezone\n  ^ here\n"}

~/Development/HomelabOS vagrant* ruby:system node:system
❯ cat group_vars/homelabos| grep common_timezone
common_timezone: 'Etc/UTC'

~/Development/HomelabOS vagrant* ruby:system node:system
❯ cat host_vars/myserver|grep common_timezone
common_timezone: 'Etc/UTC'

It's been a while since I used Ansible, but do you need to explicitly pass the variable to the role?