CSVI 9.9.0 is not offered as an available update on sites running Joomla 6.1.x. The update XML declares:
<targetplatform name="joomla" version="(5\.[01234])|(6\.[0])"/>
This regex matches Joomla 5.0–5.4 and Joomla 6.0, but not Joomla 6.1. As a result, Joomla's update checker correctly excludes the update for 6.1.x installations — #__updates remains empty and no update is presented in the Joomla backend.
Environment:
CSVI installed version: 9.8.0
Joomla version: 6.1.1
Update URL: https://rolandd.com/updates/rocsvi