You can create the automation from either phone, as long as they’re both in the same hub and connected to the same primary account it should show up in both phones.
It may help to check if your mobile presence is working, turn it off from the ST mobile settings page, delete and turn it on again (you’ll have to recreate your automations).
If the automations are giving you trouble you may want to look into a simpler solution like the Lock User Management (LUM) app which allows you create presence based users and you can select multiple conditions of present and not present to lock/unlock doors and activate codes. See this for more details: