take a look closely for 2 things;
1--it’s possible there is a tiny set-screw on the top of your tonearm base (directly above the DIN plug) that needs to be backed off (small allen key) to allow the DIN plug to be inserted; then snugged down to hold the DIN plug in the hole so the heavy phono cable does not pull it out.
or
2---you might have the DIN plug upside down. this is unlikely based on your description of the plug slot pin orientation but make sure you take a flashlight and insure that the pins inside the DIN cavity and your plug holes align.
i did look at the website for the EAT F-Note tonearm, but there are no pictures of the area where the DIN plug is to see what is going on.
btw; the DIN connector (5 pin) does include a ground pin; but not all tonearms use it. in any case, the phono cable ground is ’optional’....might not be needed. so don’t worry about it unless you get noise.