I would keep the newbies quarantine for several weeks so you can be reasonably comfortable they are not sick.
Have you looked at that one's eyes to make sure it doesn't have fluff/debris in the eye?
You can try flushing with saline to see if that makes a difference.
Watch for symptoms of runny nose, discharge from the eyes, pus, coughing, wheezing, sneezing, that would indicate respiratory illness.
Hopefully it's just fluff in the eye. Keep us posted.
I took another closer look at it and it may be half blind. I've flushed it's eyes but it seems to be hard of seeing plus it has a slightly crooked beak. I held out my hand with some food on it and it pecked at a different spot before it realized where the food was.