Egg with thin bumpy top (pics)

[Mouthwash]

My 10 month old chickens took a break laying eggs when the temp dipped into the negative 30s. We'll today we got 2 eggs but one was a little off. The shell was thin and bumpy at the top and when I slid my finger across it a piece broke off the egg white leaked out. The hole is where the piece of shell broke off with my finger. I've noticed eggs with this lumpy texture on the top before but it never was cracked and thin like this. They have access to calcium at all times (I never see them eat it) and eat egg layer crumble. No one's acting off.

 

[Eggcessive]

There may be a problem with her shell gland in the oviduct, but hard to know for sure. There can be a lot of shell problems possible, as you can see in the link below. My flock once had infectious bronchitis, if they are exposed to it, they may have all sorts of egg shell problems. Here is a good article with defects and possible causes:
https://www.backyardchickens.com/articles/common-egg-quality-problems.65923/