I see nothing at all wrong with your technique with the cuttings. They could live happy as a clam in that environment for a year and never have to grow a root. Between the spraying of the plants, spraying the dome inside, and the water in the tray they have way more then enough moisture to absorb through the leaves to survive. But at some point you have to let the children grow up and get ready to move out on their own. When I take cuttings each one is in it's own solo cup and has a clear solo cup dome which I keep on tight for the first couple days. If the cuttings are looking good (yours are looking great) I slowly start to expose them to "the real world" and do this by tilting the domes making a crack at the bottom. As you see here this allows air from outside in and reduces the amount of readily available moisture to the plant. So if it's not finding it so easy to absorb moisture through it's leaves where do you think it will get it from? If you guessed from it's roots you're right. But at this point it has no roots, but it will now start making some.
Here is my suggestion. Pick a day when you'll be home all day. First thing in the morning take the dome off all the way. Set a timer on your cell phone for 20 minutes. Heck, while you have the phone out snap a photo of the cuttings for reference. When it goes off go check the cuttings (no peeking till the timer goes off) if they look exactly the same as they did when you took the dome off set the time for another 20 minutes. This time if they look the same put the dome back on anyway and leave it on for 30 minutes. Then take it off again. This time increase the time to 30 minutes. Timer goes off, check the girls. If they look good (no wilting or bending over) let them go another 30 minutes. If they are still okay after what is a total of 1 hour you're golden. I would put the dome back on and leave it on till the next day. That next day, at some point, take the dome off and set the alarm for 1 hour. Again, check them when the alarm goes off. If they look just the same, store the dome for your next cloning job. Your plant has started making roots. And will do so MUCH quicker not being pampered.
Trust me, I was apprehensive the first time I started taking the domes off. And yes, I had plants that after 20 minutes were drooping over a bit. But in 30 minutes back under the dome they perked right back up again. I try to have the domes off my cuttings in 4-5 days.