I've noticed that line 15 on my reels is not working. It drops the matching symbols in ok but it doesn't do the attack! It's happened several times over the past few weeks but I thought I was mistaken or imagining things. However I took particular notice this time and although I got the matching symbols, once again it did not attack at all.
I've only noticed it happen with this line so far so I can't say if it happens with any other lines or not.
I've highlighted the line in the following screen capture as I wasn't quick enough to grab it when it highlighted the line in-game so you can see which line it is: N.B. In the game it shows up as a red line. I've just drawn it in grey so that it shows up more clearly.