Found this thread while trying to figure out why this happens. I am new to the chicken game and I have 5 hens. Only one of the hens is laying so figuring out which one isn't my problem for me. I noticed that the 4th egg that she layed smelled funny. I too have a sensitive nose and I immediately noticed a "hot garbage" smell. I washed it and put it in the fridge just until I could figure out if that happens to anyone else. Not all of her eggs are that way so I'm unsure what the deal is. The one she layed this morning had an odd smell too.
Fresh eggs smell rotten - Page 4
Hello! I am sorry I have no solution but only found your thread because we have exactly the same problem. I noticed this first a few weeks ago, and it seems to be exactly the same as what you're describing. We live in Italy and the weather is just warming up, so perhaps it is temperature related. I'll now start the deduction process just as you have been doing, to try to figure out which hen is laying the smelly eggs. Let me know if you do find out why it's happening and if there is any solution!