After having spent a good while with HoI3 before finally being able to hold off the massive German invasion as Norway, imagine my excitement at getting to try doing the same in a new game with UI I could understand. I was so excited that first game and I got started (Also helped that the first commander I hired randomly got the name of one of my grandfathers, it was brilliant in every way). Then imagine my surprise as I geared up for the invasion that never came. Ended up doing my own "D-Day" - liberating Denmark and ivnading Northern Germany. For my efforts I was awarded most of Germany to rule (ah I rememebr the early days when democratic nations would just take nothing in the peace deals, 'twas a gold mine to be in the Allies at the end of the war).
It is strange that they struggle to do it so often, though I will say that at least I saw the Axis try it in one of the 1.5 games, which was incredibly rare in earlier versions. I do believe they would have succeeded too in the end if not for the usual defeat of Italy and Germany to the Allies & Comintern at the time. In any case, it is a minor concern, the Axis AI struggles to handle all its fronts already, if "forcing" it to invade Norway would compromise it further I'd actually rather thigns were left as is.