I have the same thing happening here. I also ordered from McMurray Hatchering. A few of us did an order together so my friend received them on Monday. On Monday, she lost one or two, then Tuesday, she lost one of my mine (Red Star).
We picked them up Wednesday night. When they arrived here, one of the chicks was sleeping a lot but I got her to eat and drink. During the day yesterday she seemed fine again but still sleeping more than the others. I saw her eat, sleep, and poop. Poop was normal. No signs of plugged butt (only on one and I am keeping an eye on her and continuously cleaning her). Last night I lost the one that was sleeping a lot.
After that happened, another started acting the same. Sleeping a lot and now I can't get her to eat or drink. I saw her drink and eat some last night. She pooped this morning but it was a light colored running poop.
I don't have a thermometer in the box with them but they aren't huddled under the lamp and not hiding from it.
Any advice would be appreciated. I don't believe that the hatchery opens for another hour but am going to try now.