My guess is that the sulfur is from too high of a fermentation temperature. I put the bucket in the fermentation chamber which I set to 68 but when I pitched the yeast the wort was at 72. So I think it may have been too warm for the first 24 hours which was when the most vigorous fermentation happened. By the second day it was down to 66 which is where it has been for the past week.
What was your pitch rate? Mine ended up fermenting around 73 and may have hit 74 for the first two days then dropped down to 68 and hit fg at 72 hours so I bottled after 7 days. I had a slight sulfur smell around day 3 but it quickly went away and I ended up with a lot of banana which is what I wanted. After reading a lot of this thread, I am not sure anyone has pinpointed exactly the cause. I over pitched mine not knowing with a 1.5L starter.