"Infected/players would not show the "+" symbol in the inventory view when they had only items as attachments"

It seems intentional, that's in the patch notes.

intentional, but not helpful.
quick looting infected now takes like double the time.
on a server with doubled infected to vanilla, with every 2nd wearing some trash clothing item and maybe only 1 of 20 infected carry some loot only - well, now i gotta check the other 19 too, even i can see already from a mile away the orange hard hat (example) on it.
please revert. we got eyes to see.

I'm actually for this reversion.

In the past, when you got mobbed and dumped all 75 rounds of an AK into the infected, they all drop in the same area. Looking at the bodies to see if there is loot via the "+" was a lot easier than checking vacinity. This also sometimes only shows one or 2 inventories.
Then because your character breathed out now shows many more, just to hide them as you breath in again. (A VERY annoying result of a loot-splosion too, where items will dance in the vacinity screen when they are just on the edge of your characters perception. It makes it VERY frustrating picking up the item you want.)

As stated, it's obvious when an infected has outer clothing/hats/backpack on. we only really need to + to show internal items we can't see at a glance. Being able to look at the body and see if it has anything internal was very handy.

Just my 2c