"Following an inconsistent season, however, Arsenal agreed to sell him back to his original club in July 2016."
I thought so but then...
Following firm interest from Bordeaux, Arsenal have activated a buy-back clause they had previously inserted when selling the forward exactly twelve months ago.
While the Gunners have paid £3.5m to reacquire the player, the French team made it clear that they would be willing to pay £5m for the player, allowing the North Londoners to make an easy £1.5m profit through the series of transactions."
So now they stuck with him