Steps to reproduce the issue

Install 5.4.2 (current stable)
Select Stable update channel
Do not enable automated updates
Observe that a new update available 5.4.3-rc1 is reported in the system dashboard
Visit the update page
Click on the more info link to Joomla site - observe that 5.4.2 is still the current release and and no mention of 5.4.3
Just for the hell of it since you are on an unimportant test install click the Install Update on the update page
Observe that 'something' is downloaded and installed and it reports that your site has been updated to 5.4.2
Check Joomla Info and confirm version is still 5.4.2
Go back to system dashboard and observe that Joomla is Out of date and new version 5.4.3-rc1 is still showing

Expected result

New RC release should not trigger Stable channel Update Notifications
Release Candidate channel or less should trigger them

Actual result

5..4.3-rc1 Iis triggering update notification

System information (as much as possible)

Joomla 5.4.2 on Apache2 on Ubuntu 24.04 with PHP 8.3.30

Additional comments