Seaborn Restore marker edges
Give edgecolor='k' a try. This worked for me in a similar scatter plot.
Apparently, importing seaborn sets the marker edges in a matplotlib.pyplot.plot to zero or deletes them. 
e.g. plt.plot(x,y,maker='s',markerfacecolor='none')
results in a plot without markers. 
Is there a way to get the edges back?
markeredgecolor='k' has no effect.