Steps to reproduce the issue

1. Install the custom Joomla module Series Grid version 3.0.0
2. Ensure the module's manifest includes a valid <updateservers> block
3. Register the update server: https://technodrome.nasrpskom.com/updates/seriesgrid.xml
4. Confirm that the update server appears in System → Update → Update Sites
5. Ensure the update XML is valid and served with MIME type application/xml
6. The update XML offers version 3.1.1 with correct <element>mod_seriesgrid</element>, <type>module>, <client>site>, and <folder>mod_seriesgrid>
7. Go to System → Update → Extensions, click Clear Cache, then Find Updates

Expected result

Joomla should detect that the installed version is 3.0.0 and offer an update to 3.1.2 via the registered update server.

Actual result

No update is shown. Joomla does not list the module in the Extensions Update view, even though all technical conditions are met.

System information (as much as possible)

• Joomla version: 5.x (tested on 5.4.0)
• PHP version: [8.1-8.2 PHP version]
• Web server: [Apache/Nginx + version]
• Module name: Series Grid
• Installed version: 3.0.0 (confirmed in #__extensions.manifest_cache)
• Update XML version: 3.1.1
• MIME type of XML: application/xml
• XML validation: passed (no errors)
• Manual installation of ZIP works without issue

Additional comments

• The update server is correctly registered and visible in Joomla
• The update XML is publicly accessible and well-formed
• The ZIP file is correctly structured and installs cleanly
• Bumping the version to 3.1.2 and updating the XML still does not trigger Joomla to show the update
• Other extensions using the same update mechanism (e.g. components) work fine

This may be a bug in how Joomla 5 handles module updates or parses update XML for modules. Any help or insight would be appreciated!