If the fans are running at full blast, maybe you accidentally disconnected a temperature sensor?

How many PSUs are installed in the Poweredge server? In the manual it says it could be 1 or 2 and the power per PSU could be 1100W so if it is 2 * 1100W then that could explain why the UPS has problems with it.

NetworkManager’s Gnome GUI works with wireguard config files. If you are using Plasma you would need to install some alpha software to do that in the gui but you can always fall back to nmcli which also supports wireguard configs via the import command.

That is probably inspired by EN IEC 81346-2 where “X” indicates a connector of some kind and the numbers following the X identify the connector and the relative position on the connector (for connectors with multiple contacts).