Enterprise Territory Management (ETM) rules on Account are run automatically when creation of an Account. However, they do not run automatically on account update. Out of the box, here are some options available.Include the checkbox on the layout Run the ETM rules from settings, setup -> territory models -> pick a territory and run all rules assigned to the territory Here are some limitations...
What is a Apex CPU timeout?For every transaction like updating an account or creating a new contact, automation's that run in the background get 10 seconds. If your automation's take more than 10 seconds that leads to a Apex CPU timeout exception and the operations is aborted. Note that in most orgs you get an additional 5 seconds as a grace period, however...