I haven’t even played Chapel so I have no idea if it’s in the same places or not as last time, but I just played a game on Underground. A team mate Sparks threw a health pack towards me right at the top of the last set of escalators that goes to the lowest level and the pack sunk into the ground and was unable to be picked up.
Edit: I’ve been playing loads over the last two days though, and this is the first time I’ve seen this occur. So maybe it was unlucky, or just a dodgy part of the map, I’m really not sure.