Agreed, very likely shipping stress. Sadly, it happens more often than one would think.IMO it's likely shipping stress, as you're working with the odds against you if chicks are being shipped in cold (or hot) temperatures.
The wording used tells quite a bit right here in your first post - you already had one in bad shape when you recieved the package, a couple more were gone within an hour...
Shipping, temperature fluctuations, rough handling(?) can all be contributors of losing chicks.
I'm sorry that you're dealing with this, hopefully things have leveled out and the rest will make it.
TLDR, if you have Poultry Nutri-Drench on hand, give each surviving chick 2 drops orally twice a day for a couple of days. Or, if you have electrolytes like Sav A Chick use those for a couple of days then switch to plain fresh water.
I got my first order of chicks yesterday. 1/5 sapphire gems was gone pretty much on arrival and 2/5 speckled sussexs were gone within the hour even after trying my best to kickstart them. Only super sturdy ones were my starlight green eggers. Woke up this morning to 2 more sapphire gems and 2 more speckled sussexes dead. So currently have 1 ss, 2 sapphire gems, and all 5 starlights kicking. Brooder was mid 70s and brooder plate was nice and warm. Why am i losing them?? Just a bad batch? Sound like stress? Sussexs and gems never looked quite right from the get go.