Incubator temperature apparently at 35,5

[AmeliaLowe]

So the thermometer in my incubator is busted, it never goes higher than 35, but I’ve been using a secondary thermometer. I can’t keep it in the incubator 24/7 because it’s too awkward to position. I’ve been taking readings every other day, and up until yesterday, it had been reading around 37.5, the regular temperature. But when I measured yesterday, it’s been reading 35.5° C and 47% humidity. I don’t know how long this has been for. Now, I don’t know how accurate this is because the wire is a bit squished in the thermometer/hydrometer, but it’s what I’ve been going off the whole time and my eggs have developed. My incubator is second hand and the small hole to put a screwdriver in to change the temperature is damaged beyond use, so I have no idea if I can change the temperature any other way. It’s a brinsea mini eco, but an old model. It’s day 17, and I’m about to go into lockdown, all 3 chicks are still moving, look to be on track. Would this temperature drop cause any dramatic changes or ill effects? Or just delay hatching?

 

[AmeliaLowe]

In the thread I said up until yesterday that it was 37.5, this isn’t strictly true, I don’t know when this drop happened

 

[AmeliaLowe]

I’d really appreciate some insight into this