Incubating Duck Eggs Problems Hatching - Please Help (non urgent)

[NobleDucks]

I'm new to this site as well as new to incubating. We just finished up incubating and hatching duck eggs, from our own Welsh Harlequin and Khaki Campbell ducks, in a brand new Hovabator Genesis 1588. I set the temp to 99.5 during incubation and 98.5 at lockdown, the thermometer I put inside confirmed the temp. The humidity was high during the entire incubation period, about the last week I read that my humidity should be lower because it's a dry bulb vs. wet bulb reading (I may be explaining that wrong). But, the humidity was set around 60% for incubation and then 75% + for hatching/lockdown. I had to add a wet sponge to the bator to get the humidity up. I only used the humidity reading on the bator, I do know that for hatching there was more than enough humidity as I had a hard time getting the babies to dry and had to move them to the brooder to dry. We had 5 good eggs at lockdown, they were candled and I could see movement in all of them. When it came time to hatch the pips were pretty straight forward but I could see tan very dry membrane under the shell. I waited a little over 24 hours, and read every article google could find about assisting (as well as watching all the BYC videos), before intervening. I had to intervene on all 5 eggs, all had pipped but none could zip. One duck was lost, I did not intervene in time, it had pipped the shell but not the membrane and got shrink wrapped. The rest are doing well, they were more than ready to get out of their shells and were just waiting for a little help.

My question is.... What went wrong??!! Was the humidity too high for the first 25 days of incubation? I have kids and used this as a fun learning experience, we washed our hands well before handling eggs but we did candle them quite often to see what was going on inside.... should we have worn gloves? Any thoughts on this would be much appreciated. I was really hoping to order some crested duck eggs for incubation but I'm really worried the same thing will happen again and I am very discouraged. I don't want to give up on incubating because it's so much fun and very educational, but I don't want to put more baby ducks through this again!

Thank you in advance for taking the time to read this. -Victoria