The following code worked as expected in matplotlib 2.1.x but doesn't work in matplotlib 2.2.x

fig=plt.figure(1)
fig.clf()
ax=[fig.add_subplot(2,2,i+1) for i in range(4)]
for j in range(3):
      for i in range(2):
            ax[j].plot([0,i])
ax[0].legend(['1','2'], 
          bbox_to_anchor=(0.1, 1), 
          bbox_transform=ax[-1].transAxes, loc="upper left")
ax[-1].axis("off")
fig.set_tight_layout(True)

The subplots are in the wrong place and have the wrong size (mostly outside the figure window in my real ploting code ...) and its get even worse if you interact with them.

python 3.6
matplotlib 2.2.0 and 2.2.2 has been tested.