Custom field text multi-line clear value post function recording strange data in the issue history

Issue Summary

When you use a custom field text multi-line clear value post function, the history record from the issue shows strange values like the clod ID and the custom field ID in the old issue view.

This data should not be displayed on the history content.

Steps to Reproduce

1. Create a text multi-line custom field
2. Add a post-function to clear the value in a transition
3. See the history record in the old issue view

Expected Results

The History record should not have any value just the clear event

Actual Results

It is adding some IDs to history when seeing it in the old issue view

Workaround

Use the new issue view