Steps to reproduce the issue

For one domain, install Joomla twice with registering for Automated Updates and do not unregister after first installation. Enable 'Debug System' and 'Log Almost Everything'.

Expected result

Once Joomla is reinstalled for a domain and healtcheck found a working token, all out-dated, not-working tokens are deleted and no more checked.

Actual result

Every 15 minutes there is one request for each invalid token seen with 400 in HTTPS access log (CEST):

52.14.131.139 - - [19/Aug/2025:06:00:19 +0200] "GET /api/index.php/v1/joomlaupdate/healthcheck HTTP/1.1" 400 49 "-" "Joomla.org Automated Updates Server" [45056]

And corresponding 'joomla_update.php' invalid token entry (UTC):

#Fields: datetime       priority clientip       category        message
2025-08-19T04:00:19+00:00       CRITICAL 52.14.131.139  error   Uncaught Throwable of type Tobscure\JsonApi\Exception\InvalidParameterException thrown with message "Invalid token". Stack trace: #0 [ROOT]/api/components/com_joomlaupdate/src/Controller/HealthcheckController.php(52): Joomla\Component\Joomlaupdate\Api\Controller\BaseController->validateUpdateToken()
#1 [ROOT]/libraries/src/MVC/Controller/BaseController.php(730): Joomla\Component\Joomlaupdate\Api\Controller\HealthcheckController->show()
#2 [ROOT]/libraries/src/Dispatcher/ApiDispatcher.php(61): Joomla\CMS\MVC\Controller\BaseController->execute()
#3 [ROOT]/libraries/src/Component/ComponentHelper.php(361): Joomla\CMS\Dispatcher\ApiDispatcher->dispatch()
#4 [ROOT]/libraries/src/Application/ApiApplication.php(433): Joomla\CMS\Component\ComponentHelper::renderComponent()
#5 [ROOT]/libraries/src/Application/ApiApplication.php(116): Joomla\CMS\Application\ApiApplication->dispatch()
#6 [ROOT]/libraries/src/Application/CMSApplication.php(304): Joomla\CMS\Application\ApiApplication->doExecute()
#7 [ROOT]/api/includes/app.php(50): Joomla\CMS\Application\CMSApplication->execute()
#8 [ROOT]/api/index.php(31): require_once('...')
#9 {main}

System information (as much as possible)

Joomla 5.4.0-beta1, site joomla-test.heikol.de and also found by @richard67

Additional comments

This is lowest priority.