Why don’t my groups appear, in the old GUI everything is there?
The new Server Manager implementation based on Cockpit reached Beta stage and is available by default on new installations. Existing systems can add the new Server Manager module from the Software Center page. See also Accessing the new Server Manager. It is Beta yet. Thanks.
did you find something at the messages.log at the time you try to open it?
In the old GUI everything is normal.
There was some updates on Squid packages for Cockpit. Can you try to update all packages and then retry to go on Proxy into Cockpit?
Thanks for your feedback, but everything is already up to date