when do items like throwing daggers and firebombs replenish and when do they not?

hey,

i noticed that sometimes when i die or (?) rest at a bonfire these items get replenished and sometimes not. i have the feeling especially firebombs dont get replenished always, but i think sometimes they do if i remember correctly. so i would like to know under which circumstances they get replenished and under which circumstances they dont

thx :)