<C-p> does not move the cursor up correctly

[mamekoro]

FAQ

• I have checked the FAQ and it didn't resolve my problem.

Announcement

• I have checked Breaking change announcement.

Minimal reproducible full config

if has('vim_starting')
  set encoding=utf-8
endif
scriptencoding utf-8

if &compatible
  set nocompatible
endif

let s:plug_dir = expand('/tmp/plugged/vim-plug')
if !filereadable(s:plug_dir .. '/plug.vim')
  execute printf('!curl -fLo %s/autoload/plug.vim --create-dirs https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim', s:plug_dir)
end

execute 'set runtimepath+=' . s:plug_dir
call plug#begin(s:plug_dir)
Plug 'hrsh7th/nvim-cmp'
Plug 'hrsh7th/cmp-path'
Plug 'hrsh7th/vim-vsnip'
call plug#end()
PlugInstall | quit

lua << EOF
local cmp = require "cmp"
cmp.setup {
    mapping = cmp.mapping.preset.insert(),
    snippet = {
        expand = function(args)
            vim.fn["vsnip#anonymous"](args.body)
        end,
    },
    sources = cmp.config.sources {
        { name = "path" },
    },
}
EOF

Description

cmp.mapping.preset.insert() assigns cmp.select_prev_item() to <C-p>, so <C-p> should move the cursor up one position in a completion window. However, it behaves unexpectedly, as described in the "Actual behavior" section below.

Steps to reproduce

I successfully reproduced this in both my host machine (Ubuntu 22.04) and a Docker container (ubuntu:22.04).

Below is the steps to reproduce with a fresh container.
If you are testing in an already set up environment, start with step 3.

1. docker run -it --rm ubuntu:22.04
2. Install Neovim v0.9.5 in the container.

   apt update
   apt install -y curl ca-certificates git
   curl -LO https://github.com/neovim/neovim/releases/download/v0.9.5/nvim-linux64.tar.gz
   tar -xf nvim-linux64.tar.gz -C /usr --strip-components=1

3. Create ~/cmp-repro.vim as above.
4. nvim -u ~/cmp-repro.vim
5. Press i to enter insert mode.
6. Enter /. You'll see the path completion window.
7. Enter ctrl-n several times to move the cursor down.
8. Enter ctrl-p several times to move the cursor up.

Expected behavior

Each time ctrl-p is pressed, the cursor should move up one item.

Actual behavior

The first time I press ctrl-p, nothing happens.
The second time I press it, the cursor moves up two items.
Thereafter, this is repeated each time I press ctrl-p.

screencast.webm

Additional context

OS: Ubuntu 22.04
Neovim: v0.9.5