Weird character sequence appears if run from ~/.vim folder

[poetaman]

This does not happen so far in any other folder... If I run :Tree from ~/.vim folder, then instead of clean box drawing lines, I see the following weird character sequence. This happens even if vim-tree is the only plugin I load, and happens with both vim and neovim.

├── UltiSnips/
│   ├── mail.snippets
│   └── tex.snippets
├── after/
│   └── ftplugin/
│       ├── mail.vim
│       ├── qf.vim
│       ├── rust.vim
│       ├── tex.vim
│       └── vimwiki.vim
├── autoload/
│   ├── AnsiEsc.vim
│   ├── plug.vim
│   └── plug.vim.old
├── bundle/
│   ├── autoload/
│   │   └── vimwiki/
│   │       ├── base.vim

And here's the screenshot:

Relevant information:

Vim 8.2 patches 1-2890 ARM64
NeoVim v0.5.0-dev+nightly-356-gb28d458f8 ARM64
macOS BigSur 11.4 ARM64
$TERM xterm-256color