Humidity and temperature...

I would think your humidity is a little high for the first 18 days of incubation.
40% would be better.
I would have the plugs out now and maybe back in for lock down.

 

Your humidity may be a bit high during incubation. To bring the humidity up at lockdown I put some paper towel under the wire and make sure the reservoirs are filled with water. The paper towel may get wet but that is ok. I also add a half pint mason jar with warm water and a sponge in it. The sponge acts like a wick. Also if you are using a LG incubator the small holes line up perfectly so you can squirt water into the holes and the water will go into the jars to fill them and don't have to open the incubator up. The temp will change and that is ok too don't adjust it just let it settle out. Sometimes I may need to put two jars in the hatcher. I keep the humidity around 35% during incubation and bring it up to around 75% during lockdown. The plugs need to be out during lockdown. The eggs need the added airflow. If the humidity goes down during lockdown I put a straw in a hole and squirt a little warm water on the paper towel. the moisture will spread out some but that is ok. I used to incubate with the humidity around 50% and then bumping it up to 65% to 70% but since I have been doing the 35%/75% I was surprised myself how much my hatches increased. Since I have been doing my hatching like this my hatch rate has went up and I have had 100% hatches which I never thought before was possible. My hatches are or near 100%. Good luck on your next hatch...

 

Is this in a still air or forced air LG? Thanks!