Don’t worry about all this fluctuation in your incubator humidity. These temporary highs and lows don’t make a huge difference. My first time incubating humidity was a disaster as I could not get the humidity to where I wanted it. Days of it going extremely high and then being completely empty...
The pics you posted of the eggs being candled- is this your eggs at day 16? Asking because if so the air cell looks small which would indicate humidity is too high although I don’t think this causes problems until hatch?
I judge my humidity based on the size of the air cell (I hatch chicken and...
I think knowing details on temps, humidity, how often they’re turned etc can help find the problem.
I know how upsetting it is to lose them but unfortunately it comes with incubating.
I would check over your temps, humidity, turning etc and then my advice would be to stop candling so much...
Sorry for your loss.
Can I ask how you knew he had passed?
Bacteria could of gotten in or there could of been a problem where he would of died even if the shell was never cracked.