They've been making some appalling mistakes at the back, they've got 4 quality centre halves to choose from now but doesn't seem to matter which 2 they pick this season they've all got a ricket in them, probably not helped that they all seem to be picking up injuries all the time too so they've struggled to get a settled partnership. Think the loss of Lewandowski has been massive for them too, he was a real focal point to their attacks and added so much to the build up as well as providing that lethal touch, if they still had him instead of that headless chicken Immobile then perhaps they'd be getting a few more goals to counteract the clangers at the back or reduce the pressure going that way by giving opponents more to think about.
It's a transfer that doesn't seem to have worked out particularly well for anyone, I don't think Bayern look any better for the addition of Lewandowski, he certainly doesn't look as good at Bayern as he did at Dortmund and his old club are really struggling without him.