MrsAuberry00
Songster
I don't know that this helps, but sometimes they just lay smaller eggs randomly with no apparent reason. See my attached photos...the first was on 12/28 and the second was on 12/29. After these, the culprit went back to laying normal sized eggs. I do agree with aart that it could possibly be due to their new location, but since they'd been laying normally after the move, who knows? Chickens are one big mystery, my friend. 
