Ninja speaks the truth.Cigars dont get each other sick, they get sick because they're continuing to ferment. Doesn't really matter how many you have at a given point unless they're all sick or something. The KL is nice in that it helps absorb the ammonia out gassing.
Only way to know is to smoke another one. Like I said, my rule of thumb is to smoke within the first month, or wait until after month six. Generally that'll prevent you hitting a sick one.
I used to have sickness issues when I was smoking out of my 100ct. Anything that was in there for 2-6 months tasted "twangy" to me. Now that I have more space, I can keep more on hand, and now make it a point to leave most things to rest for 6mo plus. When working with small spaces/limited storage, the trick is to keep track of when you put the smokes in the humi.
Side note: if your RH is too high, you may be causing other "sour" flavors that way, too. Just something else to check out.