Well.. I see hiccups in all age birds in reality.. and getting older makes things JUST as (*if not more*) likely to hiccup or decline.. "older" being a relative term. 3 is still young for some and not for others.
Returning to lay birds from molt.. are "new" layers to some degree (in my...
It's a hiccup that can happen. Are they newer layers?
The following link doesn't have one that looks exactly like that but still a good read with a cool video..
https://www.backyardchickens.com/articles/common-egg-quality-problems.65923/
ETA: something to the effect of an inner membrane not...