Mother-Hen-Michele
Crowing
This I think is much more likely.It could just be the change in feed,... a different brand and/or change in ingredients. even if the feed was similar in nutritional content, but made up of different ingredients/different ratio, they might not be extracting full nutritional value right away - that would affect laying
The war in Europe changed a lot of grain prices worldwide. That leads to recipe changes in order to not see too big a price change for the consumer.
But the hen does not know about brands she just knows this used to be corn, now it is soy ( or other grains), so her food is different. Hens love variety in their snacks and consistency in their feed.