Grail CF SL 7 Rear Axle

Hey guys, I’m putting together my new Grail and I can’t take off the rear axle to fit the wheel, I’m worried I’ve stripped or cross threaded something…

I tried taking it off and noticed it was quite tight so I may have tried untightening it both ways. Now I can unscrew the derailleur from the axle, but the axle freely spins both ways and won’t come off the frame. I’ve tried holding the nut and turning the handle but I’ve put 20Nm through it and nothing budged, and I’m scared to try anything more.

Is there something I’m missing here or have I ruined it… pictures attached with the derailleur attached and floating.