Did you candle these eggs on the 10th and 18th day? We need to know if they were showing any signs of growth.
I would think they were, or they more than likely would have exploded.
What was your humidity and what was your temperature during incubation?
Did you have an automatic turner or were you hand turning.
On day 18 when they went into lock down, did you stop turning the eggs and increase the humidity? Did you open the incubator during lockdown?