Post functions are provided with an option to delay their execution. You need to select the number of seconds to wait until the post-function is run, a default of 1 sec to a maximum of 20 seconds.
Workflows that depend on post functions being executed in a specific order fail due to the asynchronous nature of the Connect post-functions in Jira Cloud. One of the workarounds is to delay the execution of the post-functions and thereby create a more predictable execution order. For example, on the approval of a Story you want to create sub-tasks and immediately transition them; in this case, you will have to delay the execution of the Transition Linked Issues post-function, so that the sub-tasks are created before they are transitioned. See the use case below.