I also have a Brinsea mini advanced (like it very much by the way). My first attempt involved eggs from my MF Cochin bantams; in the first set of six, five hatched; second batch all six I had placed in the incubator hatched. The hen whom I suspected laid all these eggs stopped laying during the heat of the summer and is currently going through a molt.
Trying this with six MF shipped eggs, three hatched; two were like yours; fully formed but late deaths; the third died earlier into the incubation. Second try with 10 MF shipped eggs (a different seller) all were infertile so I am unsure if something happened during the shipping (?perhaps being x-rayed?).
Shipped eggs are a gamble and financially, the success rate is likely greater using your own eggs, buying fertile eggs locally or buying chicks. Still, there's that incredible excitement waiting and watching for these eggs to hatch.
Gail
Trying this with six MF shipped eggs, three hatched; two were like yours; fully formed but late deaths; the third died earlier into the incubation. Second try with 10 MF shipped eggs (a different seller) all were infertile so I am unsure if something happened during the shipping (?perhaps being x-rayed?).
Shipped eggs are a gamble and financially, the success rate is likely greater using your own eggs, buying fertile eggs locally or buying chicks. Still, there's that incredible excitement waiting and watching for these eggs to hatch.
Gail