You have one or more workflow transitions that do not save data entered by users, and do not move the issue ticket to the new status
To perform differential diagnosis, create a new workflow (not a DRAFT of another workflow and not a COPY of another workflow) and create at least one transition.
Check your new transition for Post Functions. If there are none, then you are seeing this issue.
This issue is caused by the Workflow Plugin being disabled.
After you're done, your Workflow Plugin should look like the screenshot above.