I’m not all to familiar with the iso layouts. Non of my model Ms have wire stabilizer for any key other than spacebar.
Maybe your enter key is using a wire stabilizer and the wire is missing. Check the bottom of your enter key and see which type of stabilization it is using (geekhack.org/index.php?action=dlattach;topic=5500…). If it is using the wire and it’s missing or damaged, you can probably take the wire from the plus key and use it for enter