Start from the beginning - fully charged healthy battery?
(If I read right you swapped the coils over onto the "good" cylinder and the suspect coil worked fine?)

Did you try swapping over spark plugs to see if you can "move" the problem... or better still just start with a nice new fresh set. Fresh battery, fresh plugs, coils that you know work, check all connections (not just the obvious HT/LT coil connections) but all the blocks leading to/from the PGM all the way down to the HT caps. Also any broken or suspect wires.
You can visually check, looking for corrosion and a good fit within the terminals (but do not be tempted to sandpaper them! If you find any crud use a proprietary electrical contact cleaner and a soft cloth/brush to clean them out)

Or use a multimeter and work back from the suspect cylinder until you get to a "good" reading. Then you know the issue is between the good reading and the cylinder.

After you know the electrickery is all 100% then you can start to think about fuel or air, it needs a ready supply of all three!
Let us know how you get on...from your description my money is on a fouled plug being the culprit.

Good luck 👍