There are 2 stores and you are only sending the email from one store instead of each store sending the correct sender.
I checked in the template of one of the emails and the subject is configured correctly.
<!--@subject {{trans "Your %store_name order has been canceled" store_name=$store.frontend_name}} @-->
Even using $store.frontend_name it does't work. How can I fix this?
To configure the email of the sender is not in html template.
This configuration is in the Magento Admin Panel in stores > Configuration > Store Email Addresses, then you must verify if your website was configured using General Contact or Sales representative, in those fields there are 2 options, sender name and sender email, fill them correctly.
Important! Before fill the fields you must verify which store you selected in scope option, you said that need use for 2 stores, ok so you must fill options in order to achieve each store configurations you want.
