Is obvious that Bayern Munich don't want to lose Lewandowski. Perhaps, they still want him to play in the club next season along side with their player Sadio Mane. However, Lewandowski have made it clear that he is no longer interested in the club, and probably want to play elsewhere. Therefore, it will be unfair if Bayern fails to sell him out. He is currently Barcelona's top priority. But, I don't think Barça will be willing to pay 50 million euros which Bayern is requesting for the player.
They really don't want Lewandowski to leave and hope to keep him for another season, but on the other hand this is also quite difficult to do because Lewandowski doesn't seem to want to linger at Bayern for now.
This situation becomes quite complicated when Barcelona and Lewandowski want to immediately become a part but Bayern keep trying to get in the way and the only way if this ends is to give full clause but Barcelona are still struggling with it.