It looks like it could be a problem with the paddles or the electrics behind the paddles. As at first it's not recognising you upshifting and then it seems as though when you pressed up it actually went down a gear, into 1st. It's like the electrics or programming is messed up.
For anyone this will probably be hard to diagnose as it's electrical so take it to alfa again and make sure they run all the tests they can and maybe there needs to be some update to the code, which may not even exist if alfa hq haven't experienced the problem before. So they might tell alfa hq and they may look into it and release an update but they will take a while.