Pipping isn't a hole per say, but a breaking of the outer shell, cracks as you are describing them. I would get warm to mildly hot water and use an old sock or rag, dip in the water and quickly place in the bator. This helps pump up the humidity. Ours dropped last week during lockdown, had a pip already and added the rag with warm water. Ended with 7 of 9 hatching from the last call duck eggs for the year.
Shellie
PS
I also have a new, clean spray bottle I fill with warm water and mist locked down eggs if I have to open the bator. Helps keep humidity up.