Briess Liquid Malt Extract (LME) Syrup - CBW Sparkling Amber (3.3 lb)

Hello, I brewed a dark ale using 3.3lb of this LME mixed with 3.3lb of Briess Dark Ale LME and fermented with White Labs English Ale yeast. The result was good : rich malty flavor with coffee and dark chocolate aromas. I wasn't expecting it to have burnt caramel and bitter roasted malt undertones like stout. Also, it's been a few times I brew with LME after taking break from all-grain brewing to save time and all batches have banana off-flavors... I used different yeast, 4 differents LME and it always have the same after-taste of banana. Is it normal ? So I give 4 stars because the beers still taste better than commercial beers and I don't know if the banana after-taste is something normal with LME or just with Briess LME.