prolonged fermentation

I'm on Day 20 post yeast pitch on a Kolsch. I started cold, around 56f, as I've had good luck with that before. After about a week, it was looking like things were finished, but as I kept waiting for my Tilt to show 2-3 days of flat SG, it just keeps slowly dropping. I was initially thinking...

I’m making an all-grain Left Hand Milk Stout clone and my gravity has been stuck @ 1.030 for the last 2 weeks, it’s already been fermenting for 2 weeks prior to that (4 weeks total). The recipe has the Final Gravity stationed @ 1.016, I used a different type of yeast then I usually do (I used...