I am unable to replicate this on multiple sites and servers

I cannot reproduce the problem, same environment (thanks for detailed information) and different sites work in backend and frontend.

I am also unable to replicate this

This could be a server configuration issue as I assume your test clean install is on the same web server - perhaps related to mod_security. You should check your server error logs (or ask your web host if you dont have access).

I tested this issue on Joomla 6.0.2, and I am facing the same problem. Tags are not being saved in the database.

Unable to reproduce this issue in 5.4 and 6.1

@komalm can you describe your stack in details please

@alikon

Stack/Environment
Joomla version: 6.0.2
PHP version: 8.3.21
Database: MySQL
Web server: Apache
Browser tested: Chrome (latest)

I followed all the steps mentioned above to reproduce the issue.

Investigation: Joomla Issue #46734 - Tag Persistence
Issue Summary
Issue: #46734 - Tags added to articles are not persisted after save (Joomla 6.0.2)

Reported By: Crocodile442 on Jan 21, 2026

Description: When adding tags to an article and saving, the tags do not persist. After reopening the article, the tags field is empty. This occurs consistently and without any error messages.

Reported Environment
Joomla version: 6.0.2
PHP version: 8.3.x
Database: MySQL / MariaDB
Web server: Apache
Browser tested: Firefox (latest), Chrome (latest)
Expected vs Actual Result
Expected: The tag remains assigned to the article after saving
Actual (Reported): The tag is missing when the article is reopened, with no error or warning shown
Investigation Results
Test Environment
Joomla Version: 6.0.2
PHP Version: 8.3
Database: MySQL (joomla_db)
Database Prefix: qu11k_
Test Date: January 31, 2026
Testing Methodology

1. Browser Testing (AJAX Tag Entry Mode)
   I performed comprehensive browser testing to verify tag persistence:

Test 1: Create New Article with Single Tag
Adding tag to new article
Review
Adding tag to new article

Steps:

Created new article "Tag Test Article"
Added tag "testtag" using AJAX mode
Saved & Closed the article
Article saved in list
Review
Article saved in list

Reopened the article to verify tag persistence
Reopened article showing tag persisted
Review
Reopened article showing tag persisted

Result: ✅ Tag "testtag" persisted successfully

Test 2: Add Multiple Tags to Existing Article
Adding second tag to article
Review
Adding second tag to article

Steps:

Reopened "Tag Test Article"
Added second tag "asdfsadf"
Saved & Closed
Reopened to verify both tags persist
Result: ✅ Both tags "testtag" and "asdfsadf" persisted successfully

Test 3: Tag Entry Mode Configuration
Tags Data Entry Configuration
Review
Tags Data Entry Configuration

Configuration Checked:

Tag Entry Mode: AJAX (default)
Also tested switching to "Nested" mode
Result: ✅ Tags persist in both AJAX and Nested modes

2. Database Verification
   To confirm tags are actually being saved at the database level, I queried the tag mapping table:

Tag Mappings in Database
SELECT * FROM qu11k_contentitem_tag_map ORDER BY tag_date DESC LIMIT 10;
Results:

+---------------------+-----------------+-----------------+--------+---------------------+---------+
| type_alias | core_content_id | content_item_id | tag_id | tag_date | type_id |
+---------------------+-----------------+-----------------+--------+---------------------+---------+
| com_content.article | 4 | 22 | 2 | 2026-01-31 17:11:51 | 1 |
| com_content.article | 4 | 22 | 3 | 2026-01-31 17:11:51 | 1 |
| com_content.article | 2 | 21 | 2 | 2026-01-31 17:07:05 | 1 |
+---------------------+-----------------+-----------------+--------+---------------------+---------+
Tag Details
SELECT id, title, alias FROM qu11k_tags WHERE id IN (2, 3);
Results:

+----+----------+----------+
| id | title | alias |
+----+----------+----------+
| 2 | asdfsadf | asdfsadf |
| 3 | testtag | testtag |
+----+----------+----------+
Article Details
SELECT id, title FROM qu11k_content WHERE id IN (21, 22);
Results:

+----+------------------+
| id | title |
+----+------------------+
| 21 | asfadsf |
| 22 | Tag Test Article |
+----+------------------+
Database Verification: ✅ All tag mappings are correctly stored in qu11k_contentitem_tag_map table

Complete Testing Recording
The entire testing process was recorded and is available here:

Complete browser testing session
Review
Complete browser testing session

This recording shows:

Creating new article with tags
Saving and reopening to verify persistence
Adding multiple tags
Checking tag configuration
All verification steps
Conclusion
IMPORTANT

Issue Status: NOT REPRODUCIBLE

After comprehensive testing on the current Joomla 6.0.2 installation, the reported issue does NOT persist.

Evidence Summary
✅ Browser Testing: Tags persist correctly when:

Creating new articles with tags
Adding tags to existing articles
Using both AJAX and Nested tag entry modes
Saving and reopening articles multiple times
✅ Database Verification: Tag mappings are correctly stored in qu11k_contentitem_tag_map table with proper relationships

✅ No Errors: No JavaScript console errors or PHP errors during tag operations

I'm getting the exact same issue as reported under "Tags added to articles are not persisted after save (Joomla 6.0.2) #46734" but I'm running Joomla 5.4.3.

I created year Tags to refine the grouping of my Blog Posts on my live website (2026-Posts, 2025-Posts, 2024-Posts ... 2017-Posts). After setting the Tags in the articles, I cross-checked the posts displayed under the "by year" menu items with the articles in the admin backend sorted by date and noticed I was missing a few posts.

I assumed I hadn't set the year Tag in the missing articles. But when I went into the article, set the appropriate Tag, and saved it, the Tag disappeared with no error message.

So the issue is real and not just confined to Jooma 6.

PS. I don't know if this is a clue or not, but all of the articles where Tags won't persist are posts from 2021 to 2017. The majority of articles in this date range are saving the Tags. But a random selection is not. Also, I upgraded to Joomla 4 in late 2022, so the articles where I have issues were created in Joomla 3.x.

PPS. I may have a workaround. I saved a 2017 post with an X in the URL, and then removed the X and Saved it as a Copy. After this, I was able to set and save the year Tag. I'll report back when I've tested the workaround on the other "missing" posts tomorrow.

Update: Good news, my workaround worked! The tags persist in all the Save as Copy posts and appear in my Blog by Year menu items. Hope this helps others with a similar problem with Tags or other fields that won't persist.

@brianteeman @kkbiswal

I have the same issue in joomla 5.4.2: unable to save tags on certain articles.

It seems the problem is only present on older articles. I think it only affects articles created before an update.

In the production environment I still run joomla 5.0.0, no problems there. In the development environment, where I have updated to joomla 5.4.2, I have the problem on older articles, not on new ones. And it is really a problem since I plan some changes that require new tags. Most articles in the development environment were transferred from production and were created under joomla 5.0.0

Another indication that it only affects articles created before an update is that @tallandtrue 's workaround works: on freshly created copies I can save tags. Of course that also means extra work and modified article metadata, including loss of hits count, that brings new problems with it.

Hopefully this helps narrow it down and there will be some solution soon, or at least a better workaround.

@tallandtrue 's workaround works: on freshly created copies I can save tags

A colleague in the Australian Joomla community suggested I could have tried using the database fix tool "Update Structure" in the Admin console System -> Maintenance: Database. It was too late for me to try this, and yes, I lost my hit count (although I kept copies of the original articles with their hits).

@tallandtrue

Thank you for the reply!

joomla said the database structures are up to date. I did however select all databases and ask it to update structures anyway. Problem not solved. Still cannot save tags on old articles.

@radu147 Thanks for the update. I'll let our Joomla community know.

Take a look at ucm_content table. Maybe it has an outdated core_xreference column. Joomla database maintenance does not report these kind of problems. After I removed the column, the tags were added to the article.

Hello,

Finally got around to looking into the database thing. Thank you, @rgergo67

In the Joomla files, under administrator/components/com_admin/sql/updates/postgresql

I have found a file titled 5.4.0-2025-10-07.sql

Its content looks like this:

-- Remove wrong unique constraint from "#__ucm_content" table
ALTER TABLE "#__ucm_content" DROP CONSTRAINT "#__ucm_content_idx_type_alias_item_id" /** CAN FAIL **/;

I do not understand this very well, but I assume the constraint has not been dropped, so I have to do it manually. In the ucm_content table I have actually 3 candidate columns:

1. core_type_alias, foreign key to the content types table
2. asset_id, foreign key to the #__assets table
3. core_content_item_id, ID from the individual type table

I wouldn’t want to drop the wrong column and end up with new problems. Can anybody please advise which column to drop, if any?

that sql doesn't drop a table column it only drop a Constraint you could run it into your db with pgadmin or whatever other tool you use remeber to change #__ with you table prefix

Ran the query, The constraint did not exist, so I guess it did not fail.

I have also investigated further the issue. It seems the only articles affected are the ones where I had tags before the update and deleted them after the update. I cannot save any tags on them now. The rest of the articles seem ok, from what I have tried - there can always be something I haven't tried -, but I can save tags, delete them, save new ones. So maybe the issue is not with the ucb_content table, since ucb_content, as far as I can tell, only contains currently tagged articles?