Same symptoms here
1 - sticky saliva
2 - Impacted crop.
3 - watery and sometimes sticky stool.
4 - foul breath smell (Due to Impacted crop)
5- Lethargic (sits in one place with closed eyes)
6- the affected bird eats and drinks but on the 3rd or 4th day its condition gets worse and it dies.
A 2 months old chick died yesterday and my favourite hen died today.
I did a necropsy on both and found no worms in the crop or in the remaining digestive system.
All organs seemed normal.
A four month old chick is showing the same symptoms but I also noticed bloody stool with this one which is a symptom of coccidiosis.
Whatever this disease is it seems it affects the immune system which permits usually non fatal bacteria and viruses to become fatal.
Below pictures of recently affected chick.
I didn't take pictures of the bloody stool.
Her most recent poop was watery.
I put antibiotics and sugar in her water and will see what happens.