Trying to fetch the system updates in Discover gives this:
Opening the same link directly in Google Chrome returns an XML file, not 403.
WTF?
Yeah this is broken because we’re using the wrong link and because we’re starting to have quite some users, it’s got anti-spam blocked.
I’ve got a fix ready to use the correct URL.
You will need to upgrade to the next version with updatectl update until then.
And we have a fixed image now (thanks @stlnb), so once you have used the command line to update to 202609070254 or later, Discover updates should work once again.