Chick death help please xxx

[Tashabasha32]

Hey I hatched a duck and a chick 6 weeks ago only 1s to survive out off 8 2 died jus before hatch, now iv dun more all humidity and tempature fine (got 3 readers all configured to it n all read the same, I done automatic rolling and then when they didn't form well so now I have a chat an roll them 5-6 times a day, this lol 1 was due to hatch today but wen I candled to check for internal pip I cud feel it jus flopping about in egg no movement etc done float test nothing so opeded up n it had died like I thought, it had the saddled shaped airsac (I ordered them online so had a few like this) I'm jus worried in doin summit else wrong as this yolk is huge but looks like it ruptured if any1 can tell me wat in doin wrong!?? When I brought it out it looked like the airsac was up 1 side now n the chick was other way round n not near the airsac if that makes sense, thank u in advance xxx

 

[PalomaNova]

You need to give more details on your settings to guide you.

 

[Tashabasha32]

My incubator sits between 37.5 n 38 humidity 40-50 then last days of lockdown I put humidity to 60 like told x

 

[PalomaNova]

My incubator sits between 37.5 n 38 humidity 40-50 then last days of lockdown I put humidity to 60 like told x

What I understand your chicks and ducks died because you first did not roll the eggs. So your second load was rolled but still bad hatch ratio?
Maybe you handle them rough when rolling or they come out damaged from shipping and they cannot form well. I don't know anything about purchasing eggs though.

By the way, Last Days humidity as far as I know should be at least 70%.