If you don't have a humidity gauge it's possible your humidity has been too high throughout or too low which both can be deadly.
If I were you I would just get the chicks out into a warm brooder with food and warm water and candle the remaining eggs.
The sooner the chicks start eating and drinking the better.
I open my incubator 5,000 times during lockdown.
The eggs still in are late correct? So they may already be doomed. The chicks are alive. Help them.
I would removed the ones that have hatched immediately. While you're removing them candle the other eggs to look for signs of life.
Do you have a humidity gauge in your incubator?