Today I have spent the day watching them very often as I noticed yesterday I didn't hear any sneezing. (They have had garlic/acv water and vetRX) What I have noticed is there is no head shaking or sneezing EXCEPT while and shortly after eating. They are currently eating grower crumbles. I have not tested any other feed but could that be connected somehow? If it was respiratory, wouldn't they do it at any time? There is not a single other symptom and hasn't for 3 days. Everything else about them looks great. I'm going to wet food down and give wet food to them tomorrow and test this theory before I contact the people I got them from.
They were also vaccinated as chicks. I'm not sure what all vaccines are included or if it makes a difference in their situation as we did not vaccinate our flock.