Post functions in workflows are swapping places

Summary

The user created post functions in workflows are swapping places without any action. Thus, issues cannot be cloned or sometimes, created.

Steps to Reproduce

1. Clone an existing issue or create a new one.

Expected Results

The issue is created successfully.

Actual Results

You may get an error similar to this one:

The actual error message may vary due to the post function, but it's related to com.atlassian.jira.workflow.WorkflowException

Notes

This problem seems to affect post functions created by users or add-ons which were working properly and they haven't changed or edited recently.

Workaround

Go to project settings and double check the workflow used in the issue type.
Take a look at the Create step and check its post functions. The Creates the issue originally must be the first post function to be triggered.