Glad you have no more losses.
Do you have liquid or powdered Corid?
For the 2 that are showing signs of lethargy, I would direct oral drench them
in addition to them drinking the mixed Corid water.
Corid is mild and it won't hurt to syringe the mixed water into them several times a day as well - a lot of times birds are not drinking enough of the mixed water to get the benefit of full treatment, so encourage them to drink if you can.
Drenching instructions are here
https://www.backyardchickens.com/threads/corid-oral-drench-instructions.1211991/