Realism makes adjustments to the areas on armor that stop bullets or let bullets through based on the plate location in the armor, not all of your thorax is protected like in live tarkov.
Oooh, okay. I don't know why it didn't click before but I was looking at the armor and was like "everything is covered, so there's no way" but maybe there just wasn't plates (or strong enough) there despite the thorax being covered by 'fabric' per se. Thank you.