OK so cold eggs are a problem after day 7. However, at this stage of incubation, embryos can handle more temperature deviations.Sorry the first 2are at day 23 and the other two are at day 20. The incubators inbuilt thermometer reads 38 but it doesn't feel warm in there any more There's no reading for humidity it doesn't have it.
Is the incubator thermometer the only one you have?