If the temperatures have been low throughout the hatch, there is a chance they'll be late. Seramas oftentimes need assistance during hatch. Some people don't believe in this and think nature should take its course, but it's a personal thing. I assist if necessary. I've hatched a lot of chickens and ducks and this is how I feel. The reason it's said that you don't want to open an incubator during lockdown is because of humidity and that's more of an issue whenever you have external pips. As long as your incubator gets the temp and humidity back in a reasonable amount of time, it's OK. The link I shared is so helpful and full of knowledge.
