In specific circumstances the publish_down date is not removed correctly. This involves both one or more Joomla core tags being assigned to the article and the version management being engaged.

Steps to reproduce the issue

• Engage version management for articles
• Create one tag in com_tags
• Create an article and assign one tag to this article
• Make the article featured
• Save the article
• Create a menu item of the Featured Articles type
• Create a menu item of the Tagged items type, pointing at the tag as assigned to this article
• Check that you can see the article on both menu items indeed
• Set the Finish publishing date of the article to a date in the past and save the article
• Check that you cannot see the article on either menu item
• Remove the Finish publishing date from the article and save
• Notice that the article will appear again on the Featured articles menu item, but not on the Tagged items menu item.
• If you check in the database, in the content table the publish_down date is set to NULL but in the ucm_content table the date is still present in the core_publish_down field
• When removing the date from the ucm_content table using PhpMyAdmin, you’ll get a warming: #1265 Data truncated for column 'core_publish_down' at row 1 This results in the field containing “0000-00-00 00:00:00” instead of NULL
• The article is being displayed again on the Tagged items menu item.

Expected result

• When removing the Finish publishing date from the article, I expect the article to be displayed on the Tagged items menu item

Actual result

• When removing the Finish publishing date from the article, the article will not be displayed on the Tagged items menu item unless you remove it’s core_publish_down date from the ucm_content table.

System information (as much as possible)

• Joomla 404
• PHP 7.4.25 / mysql 5.7.32-35-log and, on another hosing:
• PHP 7.3.31 / mysql 5.6.27

Additional comments

• When changing the date instead of removing it, this is processed correctly.
• I noticed that, when removing the tag from the article, the records from the ucm_content and ucm_base tables for this article are removed completely. It is beyond my knowledge to know if this is normal behavior or not, yet I thought I should mention it.
• Thanks to Roland D for finding out what happened in the database.