It's probably the baits, not the tackle. Some baits dive more than others. The one's Mike is currently making float well, but a year or two ago they were divers. Not that there's anything wrong with subsurface slammers, I lost my good one from a few years ago and wish I had another!

But anyway, try going up in line size. Heavier line will float better, and flourocarbon is notorious for sinking :( I wouldn't got lighter than 20 lb for the small size and definitely don't go lighter than 25 for the medium.

Also, one trick to keep the lures on the surface is to retrieve them with short continuous twitches of the reel handle. The bait will stay on the surface better and it will be extremely noisy.

Good luck