I agree with the wicking issue. The picture you provided shows one of the tails darkened. Japanese cotton pads are very easy to work with so you shouldn't have an issue wicking it. Peel the pad in half, cut an appropriate length along with the fibers. Remember that the cotton is going to expand a bit. What you want to do is just twist the tip of the cotton, keep the rest of the strip as is. Thread the strip through coil while holding the other end to keep a little tension. You want to feel a slight resistance, not loose like you can pull it out easy, but not too snug to where it starts pulling your mod. Trim your tails, tuck and juice it, you'll see it slightly expand and when looking at the coil you should see no gaps between the wick and coil.
I notice the cotton to give a taste when you vape it after a new wick, it goes away quickly though. The dry taste is choking the wick. A metallic taste means a loose wick.
Be careful with sub oh, operation, make sure your batteries are proper and your build is error free in respect to shorting issues, hot spots, and the amount of current you draw based on your mod.
Check this out
Steam Engine | free vaping calculators
This site lets you see pretty accurate coil possibilities without actually having to build.