I'm using Lunarvim, one thing that the LSP module in lvim set buffer keys using

local opts = { buffer = bufnr, desc = remap[2], noremap = true, silent = true }
vim.keymap.set(mode_char, key, remap[1], opts)

The opts can only have desc but not label, here remap[2] is really the value for a label.
This turns out in which-key.keys#get_mappings method, some of the mappings we get only have value.desc but not value.label
If we use ignore_missing option here, these keybindings will be skipped by which-key
I propose a PR which add the following logic

if not value.label and value.desc then
  value.label = value.desc
end