1 fertil?

Little Chahoua

Chahoua Egg
I do not know what happens but I this second clutch same female and only 1 egg is fertile and the other egg looks 100% normal and not going bad in the incubator. what might be the problem do you think? can it be something with the male? poor sperm production or something with the female? this make me think that chahouas does not save sperm production if only 1 egg becomes fertile and not the other hmmm .. or what do you think? or is this common? regards